1️⃣ Preheat the oven:
Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish and set aside.

2️⃣ Blanch the asparagus:
Bring a pot of salted water to a boil. Add the asparagus pieces and blanch for 2-3 minutes, until bright green and slightly tender. Drain and transfer to an ice bath to stop cooking. Once cooled, drain and pat dry.

3️⃣ Make the cream sauce:
In a medium saucepan, melt the butter over medium heat. Stir in the flour and cook for 1-2 minutes until golden and bubbly. Gradually whisk in the milk and cream, stirring constantly to avoid lumps. Add garlic powder, Dijon mustard, salt, and pepper. Cook until the sauce thickens, about 3-4 minutes. Remove from heat and stir in Parmesan cheese.

4️⃣ Assemble the casserole:
Arrange the blanched asparagus in the prepared baking dish. Pour the cream sauce evenly over the asparagus, spreading it with a spatula. Sprinkle the shredded cheddar cheese on top.

5️⃣ Prepare the topping:
In a small bowl, combine breadcrumbs and olive oil. Mix until the crumbs are evenly coated. Sprinkle the breadcrumb mixture over the cheddar cheese.

6️⃣ Bake:
Place the dish in the preheated oven and bake for 20-25 minutes, or until the top is golden brown and bubbling.

7️⃣ Serve:
Let the casserole cool for 5 minutes before serving. Pair it with roasted meats or enjoy as a stand-alone dish.