Preheat oven to 350 degrees F. (180 degrees C). Line baking sheets with parchment paper or silicone liners.
Whisk together the flour, baking soda and salt. Set aside.
Using an electric mixer on medium speed, beat the butter, peanut butter and brown sugar until light and fluffy. Add the egg and vanilla and mix well.
Reduce the mixer speed to low. Gradually add the flour mixture, mixing just until combined.
Using about 2 tablespoons (30 grams) of dough at a time, roll the dough into balls. Flatten each ball into a disk. Place about ½ teaspoon of preserves in the center of the disk. Fold the edges of the disk around the preserves. Roll into a ball.
Place the cookies on the prepared baking sheets, leaving about 2 inches between cookies. Bake for 15 to 15 minutes or until the cookies arelightly browned. Allow to cool on the pans for 5 minutes. Transfer the cookies to a rack to cool completely.
Recipe courtesy of Jennifer McHenry and Quick-Shop-&-Prep 5 Ingredient Baking: Cookies, Cakes, Bars & More that are Easier than Ever to Make from Page Street Publishing.