• Preheat oven to 350 degrees F (175 degrees C).
• In a large bowl, cream together butter, brown sugar, white sugar, and peanut butter until smooth. Beat in the egg and vanilla until well blended. Combine the flour, baking soda, oats and salt in a separate bowl; stir into the creamed mixture. Fold in the chocolate chips.
  ½ cup (1 stick) unsalted butter, ½ cup light brown sugar, ¼ cup white sugar, ½ cup creamy peanut butter, 1 egg, 1 teaspoon vanilla extract, ¾ cup all-purpose flour, 1 teaspoon baking soda, ¼ teaspoon kosher salt, ¾ cup quick cooking oats, ½ cup mini chocolate chips
• Cover with plastic wrap and refrigerate for at least an hour. Make 24 dough balls (I like to do this using a cookie dough scoop to ensure uniformity) and place on an ungreased cookie sheet, preferably lined with parchment paper or a Silpat.
• Bake for 10 to 12 minutes in the preheated oven, or until just starting to get light brown. Don’t over-bake.

For the filling

• In a large bowl, cream together the butter, peanut butter, and powdered sugar until completely combined and very creamy, 2-3 minutes. Add the heavy cream and beat for another minute. Fold in the peanuts.
  3 tablespoons unsalted butter, ½ cup peanut butter, 1 cup powdered sugar, ¼ cup heavy cream

To assemble

• After the cookies are completely cooled, pipe or spread about 1 heaping tablespoon of peanut butter filling on the bottom-side of one cookie. Top with another cookie, pressing slightly to get the filling to the edge. Repeat with remaining cookies. Enjoy!