Preheat the oven to 350 degrees.
In a medium bowl whisk together eggs, granulated garlic, onion powder, salt, and pepper.
Cook spinach and drain as much liquid as possible. Divide the cooked spinach among the muffin cups.
Divide the tomatoes among the muffin cups.
Spoon 1 tablespoon of feta cheese into each muffin cup.
Pour the egg mixture evenly among the muffin cups.
Give each cup a gentle stir.
Bake for 22 minutes or until the center of the egg cups are set.
Remove each egg cup by sliding a knife around the egg cup and gently lifting it out. Serve hot.