Small Chocolate Cake

Ingredients

  • ¾ ounce unsweetened chocolate chopped
  • 1½ tablespoons unsweetened cocoa powder
  • ⅛ teaspoon instant espresso powder or instant coffee powder
  • ¼ cup boiling water
  • ⅛ cup sour cream room temperature
  • ⅛ teaspoon vanilla extract
  • 1¼ ounces all-purpose flour
  • ¼ teaspoon baking soda
  • pinch baking powder
  • ⅛ teaspoon table salt
  • 2 tablespoons unsalted butter softened
  • 1¾ ounces light brown sugar
  • 25g egg room temperature

Instructions

  1. Adjust oven rack to middle position and heat oven to 350°F. Grease a 6 inch round cake pan, line with parchment paper, grease parchment, and flour pan.
  2. Combine chocolate, cocoa, and espresso powder in small bowl. Pour boiling water over mixture, cover, and let sit until chocolate is melted, 3 to 5 minutes. Whisk mixture gently until smooth. Let cool to room temperature, then whisk in sour cream and vanilla. In separate bowl, whisk flour, baking soda, baking powder, and salt together.
  3. Using hand mixer set at low speed, beat butter and sugar in medium bowl until sugar is moistened, about 1 minute. Increase speed to medium-high and beat mixture until pale and fluffy, about 3 minutes, scraping down sides of bowl as needed. Add egg and beat until combined, about 30 seconds. Reduce speed to low and add flour mixture in 2 additions, alternating with chocolate mixture. Give batter final stir by hand.
  4. Add batter to pan, smooth top, and gently tap the pan on counter to release air bubbles. Bake cake until toothpick inserted in center comes out with a few moist crumbs attached, 20-25 minutes, rotating pan halfway through baking.
  5. Let cake cool in pan on wire rack for 10 minutes. Run knife around edge of cake to loosen. Remove cake from pan, discarding parchment, and let cool completely on rack, about 1 hour.

Notes

This makes one 6-inch round cake. (The original recipe was for a small layer cake with two 6-inch layers.)