Preheat oven to 350°F. Line baking sheet with parchment paper or reusable silicone baking mat. Set aside.
In a large bowl, cream together butter, peanut butter, and brown sugar until smooth using an electric mixer. Scrape down sides as needed. Add egg and mix until well combined.
Add flour, baking powder, and salt. Mix until no dry streaks remain. Dough will be crumbly—use hands to knead into cohesive dough.
Portion out dough into rounded tablespoons. Form into round balls using the palms of your hands. Roll and coat with granulated sugar.
Place sugar coated cookie balls on prepared baking sheet, spacing them about 2 inches apart.
Bake for 7 minutes. Remove from oven. Use a ½ teaspoon measuring spoon to create indent in the center of each cookie ball. Fill cavity with ½ teaspoon of raspberry jelly. Return to oven.
Bake 8 more minutes until edges are set and lightly golden.
Cool on baking sheet 5 minutes, then transfer to wire rack to cool completely.