Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
In a large mixing bowl, combine the peanut butter, granulated sugar, egg, and baking soda. Stir until the mixture is smooth and well combined.
Roll the dough into 1-inch balls and place them about 2 inches apart on the prepared baking sheets.
Bake the cookies for 8 to 10 minutes, or until the edges are set and the cookies are lightly golden.
Remove the cookies from the oven. Immediately press one chocolate kiss into the center of each cookie, gently flattening the cookie around the base of the chocolate.
Allow the cookies to cool on the baking sheets for 5 minutes, then transfer them to a wire rack to cool completely.
Store the cooled cookies in an airtight container at room temperature.