Preheat oven to 375ºF. Spray muffin pan with non-stick cooking spray and set aside.
Cook bacon over medium heat for 5-8 minutes. Remove the bacon before it is fully cooked and dry on a paper-towel lined plate.
Arrange each slice of bacon around the edge of each muffin cup, creating a circle around the edge.
Crack one egg into each bacon wrapped muffin cup and sprinkle with parmesan cheese. Bake 13 - 16 minutes, based on your preference for the egg consistency. At 13 minutes, the egg yolk will be more soft-boiled and at 16 minutes, more hard-boiled consistency.
Remove each cup from muffin pan with a spoon and serve with a sprinkle of salt, pepper, and the green onions.
Recipe can be scaled up or down to the number of bacon egg cups needed. If making ahead to reheat later, bake for 13 minutes, do not top with green onions, allow to cool and store in an airtight container in the refrigerator for up to 3 days or the freezer for up to a month. When ready to serve, heat, top with green onions and serve.