Adjust oven rack to middle position; heat oven to 350 degrees. Spray 5 by 9-inch loaf pan with nonstick spray, then sprinkle 1/2 cup Parmesan evenly in bottom of pan.

In large bowl, whisk flour, baking powder, cayenne, salt, and pepper to combine. Mix in cheddar or Asiago, breaking up clumps until cheese is coated with flour. In another bowl, whisk together milk, melted butter, egg, and sour cream. Gently fold wet ingredients into dry and mix until just combined (batter will be heavy and thick). Scrape batter into prepared loaf pan; level surface with spatula. Sprinkle remaining 1/2 cup Parmesan evenly over surface.

Bake until deep golden brown and toothpick or skewer inserted in center of loaf comes out clean, for 45 to 50 minutes. Cool in pan on wire rack for 5 minutes; invert loaf from pan and continue to cool until warm, about 45 minutes. Cut into slices and serve.

(Optional) FREEZING INSTRUCTIONS: Wrap cooled loaf tightly with aluminum foil and place in the freezer; it will keep for up to three months. When ready to serve, place frozen, wrapped loaf in a preheated 375-degree oven for 8 to 10 minutes until warm.