Heat oven to 350°.  Grease a 15  x 10  x 1 baking sheet and set aside.

Beat 3/4 cup butter with the brown sugar in a mixing bowl. Add egg and vanilla and continue beating until mixture is smooth.  Add in flour and salt and mix with the mixer or by hand just until incorporated.  Using an offset spatula, spread the mixture into the baking sheet almost to the edge.  It will be a thin layer.

Bake at 350° for 20 minutes or until the edges are golden brown.  Let cool slightly.

Stir together 3 Tablespoons butter, the coffee, peanut butter and powdered sugar in a saucepan on low heat.   Once mixture is melted and smooth, add chocolate chips.  Stir and let chocolate melt into the mixture until completely melted.  Remove from heat immediately and spread chocolate mixture onto cookie layer.  Spread with an offset spatula until the cookie layer is completely covered.

Cool in the refrigerator until set.  Once chocolate has hardened, remove from refrigerator and cut into 1 1/2" squares. 6 rows of 10 pieces, giving you 60 cookies.  (If it is in the refrigerator too long, you may have to let it sit out for awhile before cutting) Remove from baking sheet with a small spatula.