2 cups (250 grams) all-purpose flour1 tablespoon (15 grams) baking powder1 tablespoon (6 grams) ground cinnamon1 teaspoon kosher salt½ teaspoon ground ginger½ teaspoon ground nutmeg1 cup (200 grams) granulated sugar, plus more for topping¾ cup (168 grams) neutral oil½ cup (110 grams) firmly packed light brown sugar⅓ cup (80 grams) sour cream, room temperature⅓ cup (80 grams) whole milk, room temperature2 large eggs (100 grams), room temperature1 tablespoon (13 grams) vanilla extract2 cups (200 grams) tightly
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.
Note: Muffin liners are not necessary, though muffins will bake taller with liners and will spread wider without liners.