Move the oven rack to the middle position and preheat oven to 375 degrees F.
Line two baking sheets with parchment paper or a silicone mat.
MAKE COOKIE DOUGH:
In a large bowl or bowl of an electric mixer, beat butter until fluffy, about 30 seconds.
Add brown sugar and granulated sugar, baking soda, and salt and beat until well combined.
Beat in eggs and vanilla extract.
Add cocoa powder and beat until well combined.
Gradually add flour and mix well, scraping down the sides of the bowl.
SCOOP AND BAKE:
Divide the batter with a cookie dough scoop or drop using a tablespoon onto the prepared baking sheets. If you use a tablespoon, roll the dough into a ball.
Bake, 8-10 minutes or until edges, are firm and centers appear set, rotating the baking sheets halfway through baking.
COOL COOKIES:
Let the cookies sit on the baking sheets for 5 minutes, and then remove them from the sheets to place them on the wire racks and cool completely, about 55 minutes.
MAKE PEANT BUTTER TOPPING:
In a small bowl, stir together peanut butter and powdered sugar until smooth.
MAKE CHOCOLATE TOPPING:
In a small heavy saucepan, add chocolate chips and shortening. ***see notes
Heat over low until chocolate is completely melted, stirring occasionally.
TO FINISH:
Frost the tops of the cookies with melted chocolate and place them on the baking sheet.
Place the cookies in the refrigerator to chill until set, about 10 minutes.
Top each cookie with a teaspoon of peanut butter mixture. ***see notes
Notes
Chocolate Chips: You can also melt the chocolate chips and shortening in a microwave-safe bowl. Heat for 1 minute, stir, then continue heating for 20-30 seconds intervals until the chocolate is almost completely melted. Remove from the microwave and stir until smooth.
Peanut Butter Topping: You can either add peanut butter mixture with a spoon and smooth it out with an offset spatula, or fill a pastry bag with the mixture and pipe it on, then spread with an offset spatula.