In a mixing bowl, combine your sourdough discard, all-purpose flour, baking powder, and olive oil. Stir until a shaggy dough starts to form, then let it rest for 10 minutes to relax the gluten.

Turn the dough onto a floured surface. Roll it into 12 golf-ball-sized balls, then flatten each ball into a 3-inch circle. Ensure the edges are uniform for even cooking.

Place a cube of low-moisture mozzarella in the center of each flattened dough circle, and add your choice of filling. Pinch the edges firmly to seal the filling inside.

Arrange the sealed dough balls on a lined baking tray with the sealed side facing down. Preheat your oven to 375°F (190°C).

Bake the Sourdough Pizza Bombs for 18-20 minutes, looking for a golden-brown color and a puffed appearance.

For an extra burst of flavor, spritz the bombs lightly with water halfway through baking or brush them with garlic-infused olive oil before they go in the oven.