Preheat oven to 375°F. Line baking sheets with parchment paper.
In a large bowl, cream butter, peanut butter, granulated sugar, and brown sugar until light and fluffy.
Beat in the egg and vanilla until fully combined.
In a separate bowl, whisk together flour, baking soda, and salt. Gradually mix into the wet ingredients.
Scoop dough into 1-inch balls and roll each in granulated sugar.
Place on prepared baking sheets, spacing about 2 inches apart.
Bake for 8–10 minutes, until lightly golden and puffed.
Remove from oven and immediately press a chocolate kiss into the center of each cookie.
Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack.