In a medium-sized bowl, whisk the brown sugar, granulated sugar, baking soda, salt, egg, and vanilla until fully combined and smooth.
Fold in the peanut butter with a rubber spatula, mixing for about 2-3 minutes to until fully incorporated.
Using a 2 tablespoon cookie scoop, portion the cookie dough onto one baking sheet lined with parchment paper. Freeze cookie dough for 15 minutes.
Meanwhile, preheat the oven to 350 degrees F and line a large baking sheet with parchment paper.
Roll the frozen cookie dough in granulated sugar and place on the prepared baking sheet spaced about 2 inches apart.
Bake the cookies for 8 minutes or until barely golden on the edges. Immediately use a medium round cookie cutter or glass to scoot the edges of each cookie, making them perfectly round. Allow to cool for 2 minutes, then press a frozen kiss into each cookie. Allow to cool completely on the baking sheet.
Notes
Freeze the kisses. Unwrap and freeze the chocolate kisses for at least 15 minutes. This will ensure they hold their shape when pressed into the warm cookies!
Use a cookie scoop. Use a 2 tablespoon cookie scoop to portion the cookie dough into equally sized cookies!
Freeze the portioned cookie dough. To ensure the cookies bake up thick, don't skip the freeze time!
Scoot the cookies. Immediately after the cookies come out of the oven, use a large round cookie cutter or glass to scoot the edges and form a perfectly round cookie.