Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan.

In a large mixing bowl, whisk together the flour, baking powder, salt, garlic powder, and black pepper.

Stir in the shredded cheddar cheese and grated Parmesan cheese until evenly distributed.

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

Pour the wet ingredients into the dry ingredients and mix until just combined. Do not overmix; a few lumps are okay.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake in the preheated oven for 45-50 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.

Let the bread cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely before slicing.