Preheat your oven to 350°F (175°C). Thoroughly grease a standard 12-cup muffin tin with non-stick cooking spray or butter, ensuring the sides and bottoms are fully coated.

If not already done, cook the thick-cut bacon until very crispy. Blot away excess grease using a paper towel, then crumble the bacon into small pieces. Set aside.

In a large mixing bowl, crack all 12 large eggs. Add the heavy cream (or milk), salt, and black pepper.

Vigorously whisk the egg mixture until the ingredients are fully combined, slightly frothy, and uniform in color. This ensures the egg bites achieve maximum fluffiness.

Gently fold the shredded cheddar cheese, crumbled bacon pieces, and chopped chives (if using) into the egg mixture. Ensure the solids are evenly distributed.

Carefully pour the egg mixture into each prepared muffin cup, filling them about three-quarters of the way full. Do not overfill, as they will puff up during baking.

Bake in the preheated 350°F (175°C) oven for 20 to 25 minutes. The egg bites are done when they are fully set, puffy, lightly golden around the edges, and a toothpick inserted into the center comes out clean.

Remove the muffin tin from the oven and allow the egg bites to cool in the pan for 3 to 5 minutes. This allows them to firm up slightly. Use a small spatula or knife to gently loosen them, then transfer to a serving plate. Serve warm or store for meal prep.