Step 1: In a large mixing bowl, cream together the softened butter, 1/2 cup granulated sugar, and light brown sugar until light and fluffy, about 2-3 minutes. Scrape down the sides of the bowl as needed.
Step 2: Beat in the egg and vanilla extract until just combined. Stir in the creamy peanut butter until fully incorporated.
Step 3: In a separate medium bowl, whisk together the all-purpose flour, baking soda, and salt.
Step 4: Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Do not overmix.
Step 5: Place the remaining granulated sugar for rolling in a shallow bowl. Scoop out dough (about 1 tablespoon per cookie) and roll into smooth balls. Roll each ball generously in the granulated sugar.
Step 6: Place the sugar-coated dough balls about 2 inches apart on prepared baking sheets.
Step 7: Bake for 8-10 minutes in a preheated 375°F (190°C) oven, or until the edges are lightly golden and the centers are still soft.
Step 8: IMMEDIATELY upon removing from the oven, gently press one unwrapped Hershey's Kiss into the center of each warm cookie.
Step 9: Let the cookies cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely. The chocolate will firm up as it cools.