Cook the bacon. Place bacon in a cold skillet, turn heat to medium, and cook until crisp, 7–10 minutes, flipping as needed. Transfer to paper towels. Pour off most of the bacon fat, leaving about 1 teaspoon in the pan for flavor.

Scramble the eggs. Beat the eggs with a pinch of salt and pepper. Add a small pat of butter to the skillet (or use the bacon fat), pour in the eggs, and cook over medium-low, gently stirring until soft and just set. Take them off the heat while still a little glossy.

Prep the fillings. Crumble or chop the bacon. If using any quick-cooking veggies like spinach or green onions, stir them into the eggs at the end to wilt slightly.

Assemble the quesadilla. Place a tortilla on a clean surface. Sprinkle a thin, even layer of cheese over half the tortilla. Add the scrambled eggs and bacon, then another light sprinkle of cheese. Fold the tortilla in half to close.

Toast until crispy. Warm a nonstick skillet over medium heat and melt a little butter or add a drizzle of oil. Cook the folded quesadilla 2–3 minutes per side, pressing lightly with a spatula, until the tortilla is golden and the cheese melts.

Rest and slice. Transfer to a board and let it sit 1 minute so the cheese firms slightly. Slice into wedges.

Serve. Add salsa, avocado, or a dollop of sour cream. A squeeze of hot sauce wakes everything up.