Cook bacon, per package instructions in a skillet. Remove cooked bacon to a paper towel lined plate.

Wipe off skillet with paper towels to remove most of the rendered bacon grease.

Melt butter in same skillet over medium heat. Place 1 tortilla in heated skillet. Layer ingredients on bottom tortilla in this order: cheese, egg, 2 bacon slices, cheese and finally top with another tortilla. Cook until bottom tortilla is nicely browned and cheese is beginning to melt. Carefully flip over with a spatula. Cook other side another few minutes until crispy and cheese melted.

Cut quesadilla into quarters and serve with optional toppings.