In the bowl of a stand mixer fitted with the paddle attachment, cream together butter, peanut butter, brown sugar and granulated sugar at medium speed for 3 minutes. Scrape down the sides of the bowl and egg and vanilla extract. Mix at medium speed for 1 minute.

In a medium bowl, whisk together flour, baking soda and salt. Add the dry ingredients to the peanut butter mixture and mix at low speed until no streaks of flour remain. Cover the bowl with cling wrap and set in the fridge to chill for 30 minutes.

While the dough chills, preheat the oven to 350˚F and line two rimmed baking sheets with parchment paper.

Using a 1.5 tablespoon-size spring loaded cookie scoop, scoop 12 dough balls on each prepared baking sheet about 2 inches apart. Roll into even balls, then coat each in sugar. Bake for 10-12 minutes, or until the cookies have puffed up and the edges have set.

Remove cookies from the oven. Working quickly, press a Hershey Kiss into each cookie, then transfer to a cooling rack until the cookies are cool and the chocolate is set.