Set your oven to heat at 325°F and lightly oil a 12-cup muffin tray or prepare silicone liners.
Combine eggs, cottage cheese, garlic powder, black pepper, and salt in a blender; process until completely blended and smooth, about 30 to 45 seconds.
Distribute the chopped spinach and shredded cheddar evenly across the muffin cups.
Pour the egg mixture into each cup, filling nearly to the brim.
Place the tray in the oven and bake for approximately 24 to 26 minutes until the tops are lightly browned and a toothpick inserted in the center comes out clean.
Allow the muffins to cool fully in the tin, noting they will shrink slightly as they cool.
After cooling, gently loosen and lift each egg muffin from the tin using a small silicone spatula.