Preheat the oven to 400°F. Grease a 12-cup muffin pan or line it with paper liners.

In a large bowl, whisk together the freshly milled whole wheat flour, baking powder, salt, garlic powder, and Italian seasoning.

In a separate bowl, combine the milk, oil, and eggs. Whisk until well blended.

Add the wet ingredients to the dry ingredients and stir until just combined. Do not overmix.

Fold in the mozzarella cheese, Parmesan cheese, chopped pepperoni, and sun-dried tomatoes.

Divide the batter evenly among the prepared muffin cups, filling each about 2/3 full.

Bake for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.

Remove the muffins from the oven and let them cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.

Serve warm with marinara sauce for dipping.