Heat a large skillet over medium-high heat and add the butter. Once melted add in the frozen chopped spinach (no need to defrost prior). Stir, until heated through and no longer frozen.
Add in the minced garlic and cook until fragrant. Stir in the all purpose flour and cook an additional 2 to 3 minutes, until no flour is visible. Gradually stir in 1 ½ cups heavy cream and reduce heat to medium.
Stir in the parmesan cheese, onion powder, salt, pepper and crushed red pepper. If needed, add in up to ½ cup more heavy cream until desired creaminess is reached. Serve right away and enjoy!
*I'm using the frozen chopped spinach that comes in a microwaveable steam bag. It's not the kind that is a solid block! Look for the steam-able version for this recipe.