Peanut Butter Sandwich Cookies – A delightful peanut butter treat sandwiched with creamy filling!

Directions:
1. Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
2. In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
3. In a large bowl, beat together butter, peanut butter, granulated sugar, and brown sugar until smooth and creamy.
4. Add the egg and vanilla extract, beating until combined.
5. Gradually add the dry ingredients to the wet mixture, mixing until just combined.
6. Scoop tablespoon-sized portions of dough and roll into balls. Place them on the prepared baking sheets about 2 inches apart.
7. Flatten each cookie slightly with a fork, creating a criss-cross pattern on top.
8. Bake for 10-12 minutes, or until the cookies are golden around the edges. Let cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.
9. For the filling, beat together peanut butter, powdered sugar, vanilla extract, and butter until smooth.