Preheat oven to 375°F (190°C). Line a 12-cup muffin pan with tall paper liners, or lightly spray a 12-cup muffin pan with baking spray with flour. (See Note.)

In a medium bowl, whisk together flour, baking powder, cinnamon, salt, ginger, and nutmeg.

In a large bowl, whisk together granulated sugar, oil, brown sugar, sour cream, milk, eggs, and vanilla. Fold in flour mixture just until dry ingredients are moistened. Fold in carrots until combined and no dry streaks remain. Divide batter among prepared muffin cups (about ⅓ cup or 95 grams each). Sprinkle granulated sugar onto batter.

Bake for 10 minutes. Reduce oven temperature to 350°F (180°C), and bake until a wooden pick inserted in center comes out clean and an instant-read thermometer inserted in center registers at least 205°F (96°C), 20 to 25 minutes more. Let cool in pan for 10 minutes. Remove from pan, and let cool completely on a wire rack. Store in an airtight container for up to 3 days.