Preheat oven to 400°F. Coat 16 mini muffin cups with nonstick spray.
Cook bacon until crisp and set aside on paper towels to drain. Chop into small bits.
Whisk flour, cornmeal, sugar, baking powder, and salt in medium bowl. Whisk sour cream, buttermilk, and egg in another medium bowl. Whisk in melted butter. Stir in dry ingredients. Add bacon and chopped pepper; fold just to incorporate. Divide among prepared muffin cups, about 1 generous tablespoon per cup.
Bake mini muffins until puffed and brown around edges, 13 to 15 minutes (tops will not brown). Cool slightly. Remove muffins from pan. Serve slightly warm or at room temperature.