Cake
- ¾ cup unsalted butter, room temperature
- 2 cups sugar
- 1 egg
- 2½ cups flour
- 1 teaspoon baking soda
- ½ cup cocoa powder
- ½ teaspoon salt
- 1 teaspoon vanilla
- 1½ cups water
- 2 scant tablespoons distilled white vinegar
Frosting
- 1½ cups powdered sugar
- ¼ cup unsalted butter, room temperature
- ⅓ cup cocoa powder
- ¼ cup brewed coffee
- Ground coffee, to taste
Preheat oven to 350°. In a medium mixing bowl, beat together butter, sugar and egg. In another bowl, combine flour, baking soda, cocoa powder and salt. Stir with a fork to combine. Slowly add dry ingredients to the butter-sugar mixture and then add vanilla, water, and vinegar. Mix until well-combined.
Grease a 9″x13″ baking tin and spread batter into an even layer. Bake for 20-30 minutes, until a toothpick inserted, comes out clean.
Meanwhile, make the frosting. Combine powdered sugar, butter, cocoa, and brewed coffee, plus more fresh grounds if you want to boost the flavor. Adjust to desired taste and consistency.
Allow cake to cool completely before frosting.