Easy Pistachio and Rhubarb Cake

Spring baking always makes me excited, but I’ll admit that rhubarb used to intimidate me. It’s tart, it can be stringy, and I never quite knew what to do with it beyond the usual strawberry-rhubarb pie. Then I discovered that pairing it with pistachios creates this really nice balance. The nuts add a buttery richness that tames the rhubarb’s sharpness.

This cake has become my go-to for potlucks and weekend brunches. It looks fancy enough that people think you spent all day on it, but it’s actually pretty straightforward. You make a quick syrup for the top layer of rhubarb, grind up some pistachios, and mix everything together like you would any other cake. The semolina gives it a slightly grainy texture that I really like.

Want something different from the usual chocolate or vanilla? This pistachio and rhubarb cake might be exactly what you’re looking for. It’s moist, it keeps well for a few days, and it tastes even better the next morning with your coffee.

What Kind of Rhubarb Should I Use?

Fresh rhubarb is always your best bet for this cake, and you’ll find it in season during spring and early summer. Look for stalks that are firm and crisp with a bright color – they can range from pink to deep red, though the color doesn’t really affect the flavor. If you can only find frozen rhubarb, that’ll work too, just make sure to thaw it completely and drain off any excess liquid before adding it to your batter. One important thing to remember: always trim off and discard the leaves if they’re still attached, as rhubarb leaves are toxic and only the stalks should be used in cooking.

Options for Substitutions

This cake is pretty forgiving when it comes to swaps, so here are some options if you’re missing an ingredient:

• Rhubarb: If rhubarb isn’t in season, try using chopped strawberries, raspberries, or even tart cherries. The cake will be a bit sweeter, so you might want to reduce the sugar by about 50g.
• Pistachios: Almonds or hazelnuts work great as substitutes. Just grind them the same way you would the pistachios. The flavor will be different but still delicious.
• Semolina: You can replace semolina with the same amount of all-purpose flour or almond flour. The texture will be slightly different – almond flour makes it more moist while regular flour keeps it lighter.
• Yogurt: Sour cream or Greek yogurt are perfect swaps. You can also use buttermilk, though you might need to reduce it to about 100g since it’s thinner.
• Butter: Neutral oil like vegetable or canola works fine here. Use about 120g of oil instead of the 150g butter.
• Unwaxed lemon: If you only have waxed lemons, scrub them well under hot water before zesting. Orange zest also works nicely with the rhubarb and pistachios.

Watch Out for These Mistakes While Baking

The biggest mistake with this cake is overbaking it, which turns the tender crumb dry and crumbly – start checking around the 50-minute mark by inserting a skewer into the center, and pull it out when just a few moist crumbs cling to it.

Another common error is adding the syrup to a completely cooled cake, which prevents proper absorption – the cake should still be warm when you poke holes and pour the syrup over, allowing it to soak in deeply rather than pooling on top.

Don’t skip grinding your own pistachios from whole nuts, as pre-ground versions often lack flavor and can make your batter too dense, and be sure to cut your rhubarb into similar-sized pieces so they cook evenly throughout the cake.

Finally, resist the urge to remove the cake from the tin too early – letting it cool completely in the pan helps it hold together and prevents it from breaking apart when you slice it.

What to Serve With Pistachio and Rhubarb Cake?

This cake is perfect for afternoon tea or as a dessert with a dollop of whipped cream or vanilla ice cream on the side. The tangy rhubarb and nutty pistachios pair really well with a cup of hot tea or coffee, making it a great choice for brunch gatherings too. If you want to dress it up a bit, try serving it with some Greek yogurt and a drizzle of honey, which complements the lemon and pistachio flavors nicely. You could also add some fresh berries on the side if rhubarb is in season and you have extra fruit to use up.

Storage Instructions

Store: This cake actually gets better after a day or two as the flavors meld together. Keep it covered with plastic wrap or in an airtight container at room temperature for up to 3 days, or in the fridge for up to a week if your kitchen is warm.

Freeze: You can freeze slices of this cake wrapped individually in plastic wrap and then placed in a freezer bag for up to 3 months. It’s great to have a slice ready whenever you need a sweet treat with your afternoon tea.

Serve: If you’ve refrigerated the cake, let it sit at room temperature for about 30 minutes before serving so it softens up a bit. Frozen slices can thaw on the counter for an hour or so, and they taste just as good as fresh.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 3500-3700
• Protein: 50-55 g
• Fat: 165-180 g
• Carbohydrates: 440-470 g

Ingredients

For the syrup:

• 8 oz sugar
• 1 large lemon (zested and juiced)
• 6.8 fl oz water
• 3.5 oz rhubarb (cut into 1-inch lengths)

For the cake:

• 6 oz pistachios (I use Wonderful brand shelled kernels)
• 5.3 oz flour (I always use King Arthur all-purpose flour)
• 3.2 oz semolina
• 2 tsp baking powder
• 5.5 oz butter (softened at room temperature, about 70°F)
• 5.5 oz sugar
• 3 eggs
• 1 tsp vanilla extract
• 4.6 oz yogurt (I prefer Fage plain Greek yogurt for thickness)
• 3.5 oz rhubarb (diced into 1/2-inch pieces)

Step 1: Prepare the Rhubarb Syrup

• 8 oz sugar
• 1 large lemon
• 6.8 fl oz water
• 3.5 oz rhubarb

In a medium saucepan, combine the 8 oz sugar, lemon zest, lemon juice, and 6.8 fl oz water.

Bring to a boil over medium-high heat, stirring occasionally to dissolve the sugar.

Once boiling, reduce heat to medium and simmer for 2 minutes to create a light syrup base.

Stir in the 3.5 oz rhubarb cut into 1-inch lengths and remove from heat.

Let the syrup cool completely to room temperature—this will infuse the rhubarb flavor while you prepare the cake batter.

I like to make this first so it has plenty of time to cool and the rhubarb becomes tender and flavorful.

Step 2: Preheat Oven and Prepare Dry Ingredients

• 6 oz pistachios
• 5.3 oz flour
• 3.2 oz semolina
• 2 tsp baking powder

Preheat your oven to 160°C (320°F) and lightly grease a 9-inch round cake tin or 8×8-inch square baking dish.

While the oven heats, finely grind the 6 oz pistachios in a food processor until they resemble coarse flour with some small pieces remaining (you want texture, not a paste).

In a medium bowl, whisk together the ground pistachios, 5.3 oz flour, 3.2 oz semolina, and 2 tsp baking powder.

Set this dry mixture aside—having it ready lets you work smoothly when folding into the wet ingredients.

Step 3: Cream Butter and Sugar, Then Build the Batter

• 5.5 oz butter
• 5.5 oz sugar
• 3 eggs
• 1 tsp vanilla extract
• dry ingredient mixture from Step 2
• 4.6 oz yogurt
• 3.5 oz rhubarb

In a large bowl, beat the 5.5 oz softened butter and 5.5 oz sugar together until light, pale, and fluffy (about 3-4 minutes of beating).

Add the 3 eggs one at a time, beating well after each addition to incorporate air and create a smooth emulsion—this helps the cake rise evenly and gives it a tender crumb.

Stir in the 1 tsp vanilla extract.

Gently fold in the dry ingredient mixture from Step 2, then fold in the 4.6 oz yogurt until just combined and no flour streaks remain.

Fold in the 3.5 oz diced rhubarb pieces (the smaller pieces will distribute throughout the batter better than large chunks).

Step 4: Bake the Cake

• batter from Step 3

Pour the batter from Step 3 into your prepared tin, smoothing the top gently with a spatula.

Bake in the preheated 160°C oven for about 1 hour, or until a skewer inserted into the center comes out with just a few moist crumbs (the cake should be golden on top and spring back slightly when lightly touched).

The lower oven temperature helps the cake bake gently and evenly without over-browning the pistachio-semolina mixture.

Step 5: Soak the Warm Cake with Syrup

• cooled rhubarb syrup from Step 1

Remove the cake from the oven and let it cool for 5-10 minutes until it’s warm but no longer hot.

Using a skewer or fork, poke holes all over the top of the cake in a regular pattern (about 1-2 inches apart).

This creates channels for the cooled syrup to absorb into the cake layers.

Slowly pour the cooled rhubarb syrup from Step 1 over the entire top surface, allowing it to soak in gradually.

The warm cake will absorb the syrup beautifully, creating a moist, flavorful crumb.

Step 6: Cool and Finish the Cake

• cooled rhubarb and syrup from Step 1
• extra pistachios for garnish

Allow the cake to cool completely in its tin (about 1-2 hours, or until completely at room temperature).

Once cooled, turn the cake out onto a serving plate or leave it in the tin if preferred.

Top the cake with the soaked rhubarb pieces and extra syrup from Step 1, and scatter with extra crushed or whole pistachios for garnish and textural contrast.

I find that letting the cake cool fully in the tin helps it stay moist and tender rather than drying out.

Easy Pistachio and Rhubarb Cake

Delicious Easy Pistachio and Rhubarb Cake recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 30 minutes mins

Cook Time 1 hour hr 5 minutes mins

Total Time 1 hour hr 35 minutes mins

Servings: 8 slices

Calories: 3600

Ingredients Method

Ingredients

  

For the syrup

• 8 oz sugar
• 1 large lemon (zested and juiced)
• 6.8 fl oz water
• 3.5 oz rhubarb (cut into 1-inch lengths)

For the cake

• 6 oz pistachios (I use Wonderful brand shelled kernels)
• 5.3 oz flour (I always use King Arthur all-purpose flour)
• 3.2 oz semolina
• 2 tsp baking powder
• 5.5 oz butter (softened at room temperature, about 70°F)
• 5.5 oz sugar
• 3 eggs
• 1 tsp vanilla extract
• 4.6 oz yogurt (I prefer Fage plain Greek yogurt for thickness)
• 3.5 oz rhubarb (diced into 1/2-inch pieces)

Method

 

1. In a medium saucepan, combine the 8 oz sugar, lemon zest, lemon juice, and 6.8 fl oz water. Bring to a boil over medium-high heat, stirring occasionally to dissolve the sugar. Once boiling, reduce heat to medium and simmer for 2 minutes to create a light syrup base. Stir in the 3.5 oz rhubarb cut into 1-inch lengths and remove from heat. Let the syrup cool completely to room temperature—this will infuse the rhubarb flavor while you prepare the cake batter. I like to make this first so it has plenty of time to cool and the rhubarb becomes tender and flavorful.
2. Preheat your oven to 160°C (320°F) and lightly grease a 9-inch round cake tin or 8x8-inch square baking dish. While the oven heats, finely grind the 6 oz pistachios in a food processor until they resemble coarse flour with some small pieces remaining (you want texture, not a paste). In a medium bowl, whisk together the ground pistachios, 5.3 oz flour, 3.2 oz semolina, and 2 tsp baking powder. Set this dry mixture aside—having it ready lets you work smoothly when folding into the wet ingredients.
3. In a large bowl, beat the 5.5 oz softened butter and 5.5 oz sugar together until light, pale, and fluffy (about 3-4 minutes of beating). Add the 3 eggs one at a time, beating well after each addition to incorporate air and create a smooth emulsion—this helps the cake rise evenly and gives it a tender crumb. Stir in the 1 tsp vanilla extract. Gently fold in the dry ingredient mixture from Step 2, then fold in the 4.6 oz yogurt until just combined and no flour streaks remain. Fold in the 3.5 oz diced rhubarb pieces (the smaller pieces will distribute throughout the batter better than large chunks).
4. Pour the batter from Step 3 into your prepared tin, smoothing the top gently with a spatula. Bake in the preheated 160°C oven for about 1 hour, or until a skewer inserted into the center comes out with just a few moist crumbs (the cake should be golden on top and spring back slightly when lightly touched). The lower oven temperature helps the cake bake gently and evenly without over-browning the pistachio-semolina mixture.
5. Remove the cake from the oven and let it cool for 5-10 minutes until it's warm but no longer hot. Using a skewer or fork, poke holes all over the top of the cake in a regular pattern (about 1-2 inches apart). This creates channels for the cooled syrup to absorb into the cake layers. Slowly pour the cooled rhubarb syrup from Step 1 over the entire top surface, allowing it to soak in gradually. The warm cake will absorb the syrup beautifully, creating a moist, flavorful crumb.
6. Allow the cake to cool completely in its tin (about 1-2 hours, or until completely at room temperature). Once cooled, turn the cake out onto a serving plate or leave it in the tin if preferred. Top the cake with the soaked rhubarb pieces and extra syrup from Step 1, and scatter with extra crushed or whole pistachios for garnish and textural contrast. I find that letting the cake cool fully in the tin helps it stay moist and tender rather than drying out.