Preheat & Prep. To start, preheat the oven to 375 degrees F. Line a baking sheet with parchment paper or lightly grease, and set aside.
Prep The Bagel Halves. Then, slice each bagel in half and brush the cut side of each bagel half with a little olive oil. Sprinkle with garlic salt and place on the prepared baking sheet. Bake for 8-10 minutes to slightly toast. (It doesn't need to brown, but you want the surface to get a little crispy!)
Layer With Toppings. Use an offset spatula to spread 2-3 Tablespoons of pizza sauce on each toasted bagel half. Then, add mozzarella cheese and pepperoni slices.
Bake Pizza Bagels for 5-7 minutes, or until the cheese is fully melted. If desired, you can put them under the broiler for 1-2 minutes at the end for a bit more browning and bubbling.
Finish The Pizzas. After removing them from the oven, sprinkle bagel pizzas with extras like parmesan cheese, herbs, pepper, or red pepper flakes.
Serve & Store. Enjoy warm! Store leftover bagel pizzas in an airtight container in the fridge 1-2 days. Reheat in the oven or air fryer for best results!