Start by rinsing fresh spinach under cold water. In a large pot, add a splash of water and bring it to a simmer over medium heat. Cook for 3 to 5 minutes until wilted, then drain and chop.

In a medium saucepan, melt butter over medium heat. Add minced garlic and cook for about 1 minute until fragrant. Gradually whisk in flour, then stir in heavy cream. Once thickened, mix in Parmesan cheese and season with onion powder, salt, and pepper.

Combine the chopped spinach with the creamy sauce in a large mixing bowl and mix thoroughly.

Preheat the oven to 350°F (175°C). Grease a 2-quart casserole dish. Pour the spinach mixture into the dish and sprinkle breadcrumbs on top.

Bake for 20 to 25 minutes, until the top is golden brown and bubbly. Let cool briefly before serving.

Scoop out portions and serve warm, enjoying the creamy goodness.