Place the 8 bagel halves, cut side up, on a baking sheet. Divide the pizza sauce evenly between the bagel halves, spreading an even layer on each. Top each with cheese, then pepperoni. If desired, sprinkle with the Italian seasoning and the red pepper flakes.
Bake in the preheated oven until the cheese is melted, 10-12 minutes.
Notes
Nutrition information provided as an estimate only. Various brands and products can change the counts. Any nutritional information should be used as a general guide.