Follow these simple instructions to create perfect Egg and Cheese Breakfast Muffins every time. Each step is designed to ensure your muffins are fluffy, flavorful, and evenly cooked.

1. Preheat Your Oven and Prepare the Muffin Tin: Begin by preheating your oven to 375°F (190°C). This ensures the oven is at the correct temperature when you place the muffins in, allowing them to bake evenly. While the oven preheats, prepare a 12-cup muffin tin. You can either grease each muffin cup thoroughly with cooking spray or line them with paper or silicone muffin liners. Liners make for easy cleanup and muffin removal, but greasing directly can result in slightly crisper edges.
2. Whisk the Eggs and Milk: In a large mixing bowl, crack the 6 large eggs. Add the ½ cup of milk to the bowl. Using a whisk, thoroughly whisk the eggs and milk together until they are well combined and slightly frothy. Whisking incorporates air, which helps to create a lighter texture in the muffins. Continue whisking for about 1-2 minutes to ensure everything is properly mixed.
3. Add Dry Ingredients to Wet Ingredients: In the same bowl with the egg mixture, add the 1 ½ cups of all-purpose flour, 2 teaspoons of baking powder, ½ teaspoon of salt, and ¼ teaspoon of black pepper. Use the whisk to gently combine the dry ingredients into the wet ingredients. Mix until just combined. Be careful not to overmix the batter. Overmixing can develop the gluten in the flour, resulting in tough muffins. A few streaks of flour are okay at this stage.
4. Incorporate the Cheese and Optional Add-ins: Now, add the 1 ½ cups of shredded cheese to the batter. If you are using any optional vegetable add-ins, such as diced bell peppers, onions, spinach, or mushrooms, add them now as well. Gently fold in the cheese and any add-ins using a spatula or spoon until they are evenly distributed throughout the batter. Folding ensures the ingredients are incorporated without overmixing the batter.
5. Fill the Muffin Cups: Using a spoon or an ice cream scoop, evenly distribute the batter into the prepared muffin cups. Fill each muffin cup about ¾ full. Leaving a little space at the top allows the muffins to rise properly without overflowing. If you want to ensure even baking and portion sizes, you can use an ice cream scoop to measure out equal amounts of batter for each muffin cup.
6. Bake the Muffins: Place the filled muffin tin in the preheated oven on the center rack. Bake for 20-25 minutes, or until the muffins are golden brown and a toothpick inserted into the center of a muffin comes out clean. The baking time may vary slightly depending on your oven and the size of your muffin tin. Start checking for doneness around 20 minutes.
7. Cool and Serve: Once baked, remove the muffin tin from the oven and let it cool in the tin for a few minutes. This allows the muffins to set slightly and makes them easier to remove. After a few minutes of cooling, carefully remove the muffins from the muffin tin and place them on a wire rack to cool completely, or serve them warm immediately. Cooling on a wire rack prevents the bottoms of the muffins from becoming soggy.