Preheat the oven to 350įF. Spray an 9- x 5-inch loaf pan with non-stick spray.
In a large bowl, stir together the flour, baking powder, salt and cayenne pepper. Stir in the grated cheeses, tossing to blend and get rid of clumps.
In a medium bowl, stir together the milk, sour cream, butter and egg. Add it to the dry ingredients and gently stir with a spatula just until combined. Donít overmix, or your bread will be tough.
Pour the batter into the prepared pan. If you like, sprinkle the top with additional grated cheddar or Parmesan cheese.
Bake for 45-50 minutes, until the loaf is golden and the top is springy to the touch. Cool in the pan on a wire rack. Makes 1 loaf.