Meg Ray and Caitlin Alissa Williams usually bake this wonderfully rich cocoa crème fraîche batter in a loaf pan, but it bakes even faster in cupcake tins. If the amount of batter fills more than one standard 12-cup muffin pan, just bake the rest in sturdy foil baking cups set on a baking sheet.
1 stick plus 6 tablespoons unsalted butter, softened
1 cup sugar
3 large eggs
1 teaspoon pure vanilla extract
3/4 cup crème fraîche, at room temperature and stirred until runny, plus more for serving
Preheat the oven to 350°. Line a 12-cup muffin pan with foil baking cups. Put 4 additional foil cups on a small baking sheet.
Sift together the flour, cocoa powder, baking powder, salt and baking soda. In a large bowl, beat the butter and sugar until light and fluffy. At medium speed, add the eggs one at a time, beating until each one is fully incorporated before adding the next. Add the vanilla. At low speed, alternately beat in the dry ingredients and the 3/4 cup of crème fraîche in 2 batches.
Spoon the batter into the foil cups, filling each one two-thirds full. Bake the cupcakes for 15 minutes, or until springy when gently pressed and a cake tester inserted in the center comes out clean. Let cool slightly, then remove from the pan. Place a dollop of crème fraîche on each cupcake and serve.