Preheat oven to 375 degrees.
Line cookie sheet with parchment paper or lightly grease.
Whisk together flour, cocoa, baking soda and salt. Set aside.
Cream sugars, butter and peanut butter together until light and fluffy.
Add in egg, vanilla and water and beat until well blended.
Gradually stir in dry ingredients.
Fold in one cup of Reese's minis.
Scoop out rounded tablespoons of cookie dough onto prepared cookie sheet. Dough is very thick.
Flatten each cookie slightly and add 1-2 Reese's minis to the top of each cookie.
Bake for 7-8 minutes or until they are set. Do not over bake.
Remove from oven and let cool on a rack.