Preheat your oven to 375°F and generously butter a 12-cup muffin tin with all 2 tablespoons of butter. This prevents sticking and ensures your heartwarming egg muffins release cleanly after cooling.

Crack all 12 eggs into a large mixing bowl and whisk vigorously with milk until completely combined and pale yellow. Add salt, black pepper, and garlic powder, whisking once more to distribute seasonings evenly throughout.

Divide your diced bell peppers, zucchini, onion, spinach, and smoked turkey evenly among the 12 muffin cups, layering vegetables first. Distribute shredded cheddar cheese across each cup, reserving a small pinch for topping if desired.

Pour the egg mixture carefully into each prepared muffin cup, filling about three-quarters full to allow for slight expansion during baking. Bake for 22-25 minutes until cozy summer egg muffins recipe yields golden-brown tops and a set center.

Remove from the oven and let cool in the tin for 5 minutes before carefully running a knife around the edges. Turn the tin upside down onto a cooling rack and gently tap the bottom until all muffins release completely.

Once fully cooled, these egg muffin cups transfer easily to storage containers for refrigeration or freezing as needed. Enjoy them cold or reheat briefly for that cozy savory meal prep experience you crave.