- Preheat the oven to 375°F. Lightly grease (or line with parchment) two baking sheets.
- In a medium-sized bowl, whisk together the flour, cocoa, baking soda, and salt.
- In another bowl, beat together the sugars, butter, and peanut butter until light and fluffy.
- Beat in the vanilla, egg, and water, then stir in the dry ingredients, blending well.
- Stir in the mini peanut butter cups.
- Scoop rounded tablespoonfuls of dough onto the prepared baking sheets; a tablespoon cookie scoop works well here. Flatten each cookie to about 1/2" thick.
- Bake the cookies for 7 to 9 minutes, or until they're set and you can smell chocolate. Remove them from the oven, and cool on a rack.
- Yield: about 3 dozen cookies.