One-Bowl Chocolate Cake

Tap an ingredient or step to check it off.

1. 1Step 1: Place a rack in the center of the oven and preheat to 350°F. Grease an 8-inch square pan with butter or nonstick spray. Line the pan with a strip of parchment paper that hangs over two opposite sides.
2. 2Step 2: In a large bowl, whisk the brown sugar and eggs until pale and foamy, about 1 minute. Add the yogurt, oil, vanilla, and salt. Whisk until smooth and emulsified. Add the cocoa powder and whisk until well-combined and smooth.
3. 3Step 3: Add the flour, baking powder, and baking soda and whisk until well-combined and smooth. Fold in the chopped chocolate, if using.
4. 4Step 4: Pour the batter into the prepared pan, tap gently on the counter to release air bubbles, and smooth the top with an offset spatula.
5. 5Step 5: Bake until puffed and a tester inserted into the center comes out clean, 35 to 45 minutes. Let cool on a rack for 15 minutes, then lift out with the parchment and cool completely.
6. 6Step 6: For the glaze: In a bowl, whisk the confectioners' sugar and cocoa until combined and no lumps remain. Add the butter, salt, and 2 tablespoons boiling water and quickly whisk until smooth. If too thick, add drops of water until pourable.
7. 7Step 7: Immediately pour the glaze over the cooled cake. Let set for 20 minutes before slicing. Store covered at room temperature or in the fridge for up to 3 days.
8. 8Step 8: Pan variations: For a Bundt pan: Double the cake ingredients and bake in a prepared 15-cup Bundt pan for 50 to 60 minutes until a skewer comes out clean. Cool in the pan for 10 minutes, then invert onto a rack. Double the glaze. For cupcakes: Fill paper-lined cupcake tins no more than halfway and bake for 12 to 18 minutes (makes 12 to 18). For a loaf: Bake in a 9x5x3-inch loaf pan for 55 to 65 minutes; use half the glaze. For a round pan: Bake in a 9-inch round pan for 35 to 45 minutes.