Ingredients
Cake
- 6 tablespoons (85 grams) unsalted butter, at room temperature
- 3/4 cup (145 grams) firmly packed dark brown sugar
- 2 tablespoons (25 grams) granulated sugar
- 1 large egg
- 1 large egg yolk
- 3/4 cup (175 ml) buttermilk (see Notes for other options)
- 1 teaspoon (5 ml) vanilla extract
- 1/2 cup (41 grams) Dutch cocoa powder
- 1 cup (125 grams) all-purpose flour
- 1/4 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 teaspoon table or fine sea salt
Frosting
- 2 ounces (55 grams) unsweetened chocolate, melted and cooled
- 1 1/2 cups (180 grams) powdered sugar (sifted if lumpy)
- 1/2 cup (4 ounces or 115 grams) unsalted butter, at room temperature
- Pinch of fine sea salt (optional)
- 1 tablespoons cream or whole milk
- 1/2 teaspoon vanilla extract