- 2 cups, spoon and level all-purpose flour
- 1 cup natural cocoa powder, sifted
- 2 1/2 teaspoons baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
- 2 eggs plus 1 egg yolk
- 1 1/4 cups granulated sugar
- 1/2 cup canola or vegetable oil
- 1 1/2 cup sour cream
- 1 tablespoon vanilla extract
- 10 1/2 ounces chocolate chips and/or chopped chocolate, divided*
- sparkling sugar, for tops
Preheat oven to 375ºF and grease a standard 12-cup muffin tin with cooking spray, wiping off any excess on the top of the tin.
In a bowl, whisk together the flour, cocoa, baking powder, baking soda, and salt.
In the bowl of a stand mixer fitted with the whisk attachment (or using a handheld electric mixer), begin beating the eggs on medium-high speed. Slowly stream in the sugar while beating and continue to beat until the mixture is pale and thickened and ribbons down from the beater when lifted before settling back down into the batter. Wipe down the bowl and beater as needed.
Beat in the oil until fully incorporated. Wipe down bowl and beater and beat in sour cream and vanilla until evenly incorporated.
Add the dry ingredients to the wet and fold in just until only a few visible streaks remain. Add 8 1/2 ounces of the chocolate and fold in just until all ingredients are evenly incorporated.
Spoon the batter evenly into the prepared muffin cups, smoothing the tops if needed but keeping the scoops mounded. Top each with some of the remaining chocolate and sprinkle with sparkling sugar.
Bake muffins in preheated oven for 10 minutes, and then reduce heat to 350ºF and bake another 5-10 minutes, until a toothpick inserted into the center of one comes out free of wet batter. Cool muffins in pan for about 15 minutes before transferring to a wire rack to cool completely. Store muffins in an airtight container at room temperature, or in the refrigerator to keep for more than a few days.