For the peanut butter filling: Line 2 regular baking sheets and 1 smaller one with parchment paper.
Whisk together the peanut butter and confectioners' sugar in a medium bowl until smooth. Using a tablespoon scoop, portion into 18 rounds and place them on the small parchment-lined pan. Put them in the freezer to firm up, at least 20 minutes.
Preheat the oven to 375 degrees F.
For the cookie dough: Meanwhile, in the bowl of an electric mixer fitted with a paddle attachment, cream together the brown sugar, butter and granulated sugar until nice and combined, about 2 minutes. Add the vanilla and egg and beat until smooth, scraping the bowl if necessary to make sure everything is incorporated.
In a separate bowl, stir together the flour, coffee granules, baking soda, baking powder and salt. Add the dry ingredients to the mixer gradually, mixing on low until totally incorporated. Stir in the chocolate chunks.
Scoop the cookie dough into eighteen 2-tablespoon portions and with your palm, flatten each scoop into a disc.
Place one peanut butter round in the center of a dough disc. Bring the edges of the dough around the peanut butter round and enclose completely. Roll to ensure all the peanut butter is covered. Flatten with your palm, creating a disc shape once again. Repeat with the remaining peanut butter rounds and dough discs. Split the finished discs between the 2 lined baking sheets.
Bake until the cookies are golden brown, 10 to 11 minutes. Transfer the cookies to a cooling rack and allow them to cool slightly before eating, 5 to 7 minutes.