Brush one side of each tortilla with reserved bacon drippings. Place tortillas, bacon-dripping side down, onto large cutting board. Place 2 slices cheese onto half of each tortilla. Top evenly with bacon, tomato and avocado. Fold each tortilla in half over filling. Heat 12-inch skillet over medium heat; place 2 quesadillas into skillet. Cook, turning once, 5-6 minutes or until golden brown on each side and cheese is melted. Cut into wedges. Serve with salsa and sour cream.