Preheat oven to 350 F and grease a 9x5-inch loaf ban with non-stick cooking spray. Set aside.
In a large bowl, whisk together the flour, baking powder, salt, cayenne, and black pepper.
Mix in the cheese cubes until they are coated in the flour mixture.
In a separate bowl, whisk together the milk, sour cream, melted butter, and egg.
Gently fold the wet mixture into the flour mixture until just combined. The mixture will become thick.
Pour the batter into the prepared loaf pan, and bake for 45 minutes.
Remove from the oven, cool for 10 minutes, remove from pan, and let cool on a wire rack.