Dark chocolate cookie base
- ½ cup unsalted butter, softened
- ½ cup granulated sugar
- ⅓ cup light brown sugar, packed
- 1 large egg
- 1 teaspoon vanilla extract
- 1 cup all-purpose flour
- ⅓ cup dark cocoa powder (Dutch-processed preferred)
- ½ teaspoon baking soda
- ¼ teaspoon salt
Topping