Preheat the oven to 350 degrees F. Lightly grease a 12-cup muffin tin with the cooking spray.
Layer three slices of Canadian bacon in each muffin cup, overlapping them slightly. They will come over the sides of the muffin cup.
Place 1 tablespoon of marinara sauce in each cup, spreading it around lightly.
Add 2 tablespoons of the spinach, then 2 tablespoons of cheese, to each cup. They will be fully loaded.
Bake for 25-30 minutes, until the cheese is melted and golden brown.
Pop the no crust pizza bites out using a fork and enjoy