Preheat your oven to 350°F and lightly grease a 9x13 inch baking dish. While the oven heats, wash the asparagus and trim the woody ends, then cut into 2-inch pieces for even cooking. Crush the butter crackers into bite-sized crumbles (not too fine—you want some texture to remain). Measure out the cream of mushroom soup, cheddar cheese, and onion powder into separate bowls for easy assembly.

Bring a pot of salted water to a boil and add the prepared asparagus pieces. Cook for exactly 4 minutes—this brief blanch softens the asparagus while keeping it tender-crisp and removing any bitterness. Immediately drain in a colander and let sit for a moment to stop the cooking process. I like to save a handful of the crunchiest pieces to place on top for visual appeal before baking.

In a large bowl, combine the drained asparagus with the cream of mushroom soup and onion powder, stirring gently until the asparagus is evenly coated. Pour this mixture into the prepared baking dish, spreading it in an even layer. The soup creates the creamy foundation that will bind everything together during baking.

Sprinkle the cheddar cheese evenly over the asparagus mixture, then top with the crushed butter crackers. Pour the melted and slightly cooled butter evenly over the entire casserole, allowing it to seep down through the cracker layer—this ensures the topping gets crispy and golden rather than soggy. I find that letting the butter cool slightly prevents it from immediately melting the cheese unevenly.

Place the casserole in the preheated 350°F oven and bake for 15-20 minutes, until the top is golden brown and the filling is bubbling around the edges. The exact time depends on your oven and how full the dish is—start checking at 15 minutes. Once ready, remove from the oven and let rest for 2-3 minutes before serving to allow the casserole to set slightly.