01 - Preheat the oven to 375°F. Lightly grease a 6-cup muffin tin with nonstick cooking spray.
02 - Cook bacon strips in a skillet over medium heat for 5-6 minutes until beginning to crisp but still pliable. Drain on paper towels.
03 - Whisk together eggs, whole milk, shredded cheddar, salt, and black pepper in a mixing bowl. Stir in chopped chives if using.
04 - Pour egg mixture evenly into the prepared muffin cups, filling each about three-quarters full.
05 - Twist each bacon strip into a loose spiral and place on top of each filled muffin cup.
06 - Bake in the preheated oven for 15 to 18 minutes until eggs are set and slightly golden.
07 - Allow egg cups to cool for 2 to 3 minutes before carefully removing them from the muffin tin. Serve warm.