Step 1

Prepare the Muffins: Preheat oven to 350°F. Lightly grease a 24-cup miniature muffin pan with cooking spray. Stir together sour cream, oil, egg, vanilla, and 1/2 cup sugar in a small bowl. Whisk together flour, baking soda, salt, 1/2 teaspoon cinnamon, and 1/4 teaspoon nutmeg in a medium bowl. Whisk sour cream mixture into flour mixture. (Batter will be very thick.) Spoon 1 tablespoon of batter into each prepared muffin cup, keeping batter rounded on top.

Step 2

Bake in preheated oven until golden and springy when touched lightly on top, 10 to 12 minutes. Cool in pan 5 minutes. Remove from pan to a wire rack; cool completely, about 15 minutes.

Step 3

Prepare the Coating: Place melted butter in a small bowl. Whisk together 1 cup sugar, 1 1/2 teaspoons cinnamon, and 1/2 teaspoon nutmeg in another small bowl.

Step 4

Dip 1 Muffin in butter; immediately dredge in sugar mixture, and place on a serving platter. Repeat with remaining Muffins, butter, and sugar mixture.