Preheat your broiler to high and line a baking sheet with parchment paper.
Place the mini bagel halves on the baking sheet with the cut side up.
Spread a thin layer of pizza sauce on each bagel half and sprinkle evenly with shredded mozzarella cheese.
Place mini pepperoni slices and olives (if using) over the cheese. Add a dash of dried oregano if desired.
Place the baking sheet under the broiler for 3 to 4 minutes until the cheese is bubbly and lightly browned. Remove from the oven, let cool slightly, and serve warm. Garnish with thinly sliced basil if desired.