Preheat the oven to 375ºF. Finely chop or shred your chosen add-in ingredients. Add 2 Tbsp of add-ins to each well of a non-stick 12 muffin tin. If your non-stick pan is older or the finish is a bit worn, you may want to grease the wells first with butter or oil.
Add the eggs, cottage cheese, salt, and pepper to a large blender. Purée for about 30 seconds or until smooth.
Pour the egg mixture into the wells of the muffin tin, dividing evenly between each well. It should fill them almost to the top.
Bake the egg muffins in the preheated oven for 18 minutes, or just until the centers no longer look wet and they are barely golden around the edges. Avoid overcooking them or they'll become spongey. They'll puff up quite a bit as they bake and deflate as they cool. This is normal.
Allow the muffins to cool in the muffin tin just enough to handle, then loosen them gently with a knife and remove them from the tin. Allow the egg muffins to finish cooling on a wire rack. Enjoy warm or refrigerate until ready to eat.
*4% milkfat cottage cheese creates the softest egg muffins. You can use a lower fat cottage cheese, but it will affect the texture slightly.**To make this recipe as budget-friendly as possible, check your fridge for any leftover ingredients that can be used as add-ins. You can use any meat, cheese, or vegetables. You'll need 2 Tbsp total for each muffin. Make sure they're finely chopped or shredded. We used spinach & feta, sausage & onion, broccoli & cheddar, and red pepper & goat cheese.