Preheat oven to 375°F (190°C) and grease a muffin tin or line with muffin liners.
In a mixing bowl, whisk together eggs, milk, salt, pepper, garlic powder, and paprika.
Add cheese, bell peppers, onions, and cooked bacon or sausage. Stir to combine.
Pour the egg mixture evenly into the muffin tin, filling each cup about 3/4 full.
Bake for 18-20 minutes or until eggs are fully set and lightly golden.
Let cool for a few minutes before removing from the muffin tin. Serve warm or store for later.