01 - Preheat oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease thoroughly.
02 - Boil macaroni in salted water until just al dente following package directions. Drain and set aside.
03 - In a large mixing bowl, whisk together all-purpose flour, cornmeal, baking powder, salt, and black pepper until evenly combined.
04 - In a separate bowl, beat eggs, then whisk in whole milk, sour cream, and melted butter until smooth.
05 - Add wet ingredients to the dry mixture and stir gently until just combined; do not overmix.
06 - Fold in cooked macaroni, cheddar cheese, mozzarella cheese, and sweet corn kernels until distributed evenly throughout the batter.
07 - Spoon batter evenly into prepared muffin cups, filling each about three-quarters full.
08 - Bake in the center of the oven for 22 to 25 minutes, or until muffin tops are golden and a toothpick inserted in the center comes out clean.
09 - Cool muffins in the tin for 5 minutes, then transfer to a wire rack. Serve warm or at room temperature.