For the cauliflower crusts: Preheat oven to 450°F.
Line a baking sheet with parchment paper and brush with olive oil.
Pulse a few florets of cauliflower at a time in your food processor until the cauliflower pieces are the size of couscous, about 3 cups.
Next, bring ½ cup of water to a boil in a small saucepan. Add the cauliflower to the pan. Stir. Turn the heat off and cover the pan. Let the pan sit covered for 10 minutes.
Then remove the lid. Transfer to a cheesecloth and twist cheesecloth into a pouch. Squeeze out as much of the moisture as possible, almost 1 cup of liquid. It is important for the cauliflower to be dry.
Then place in a large mixing bowl and add egg, parmesan cheese, salt, and pepper. Mix well.
Divide into 4 sections on the oiled parchment paper. Shape into circles to fit each ramekin by placing the ramekin upside down like a cookie cutter.
Bake for 10-15 minutes and set aside.
For spinach filling:
Meanwhile, thaw spinach. Squeeze dry and drain.
Turn oven down to 350℉.
Soften cream cheese in a skillet over a low flame. Add drained spinach to softened cream cheese keeping over a very low heat. Add garlic, salt, and parmesan.
By now your cauliflower crusts should be finished baking. Using a spatula, gently place one baked cauliflower crust on the bottom of each ramekin. Then cover with one slice of Muenster cheese. Fill with your spinach mixture and cover with another layer of two slices of Muenster cheese.
Bake at 350℉ for 20-25 minutes.