Preheat your oven to 375°F. Grease a 9x5-inch loaf pan.
In a large mixing bowl, combine the flour, baking powder, salt, garlic powder, and Italian seasoning. Mix well.
Add the shredded mozzarella cheese and pepperoni to the dry ingredients, stirring until evenly distributed.
In a separate bowl, whisk together the milk, olive oil, and egg until well combined.
Pour the wet ingredients into the dry ingredients and mix until just combined. Do not overmix.
Transfer the batter to the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for 30-35 minutes or until the top is golden brown and a toothpick inserted into the center comes out clean.
Allow the bread to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.