Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a medium bowl, mix together the peanut butter, granulated sugar, egg, and baking soda until well combined.
Roll the dough into 1-inch balls and place them 2 inches apart on the prepared baking sheet.
Flatten each ball slightly with the palm of your hand or the bottom of a glass.
Bake for 8-10 minutes, or until the edges are lightly golden.
Remove the cookies from the oven and immediately press one Hershey’s Kiss into the center of each cookie.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.