For Cookies

1. Line a single baking sheet with parchment paper and set aside.
2. In the bowl of a stand mixer fitted with the paddle attachment, beat butter, 1/2 cup granulated sugar, and brown sugar at medium speed until light and fluffy, about 2-3 minutes.
3. Scrape down sides of bowl as needed.
4. Add egg and egg yolk, mixing well to combine.
5. Add peanut butter and vanilla bean paste, beating until well combined.
6. In a medium bowl, whisk together flour, baking powder, baking soda and salt.
7. Gradually add flour to the butter and egg mixture, beating on low speed until just combined.
8. Use a cookie scoop to scoop dough into mounds and place on prepared pan.
9. To ensure all cookies are the same size once baked, weight the cookies. I made them 26 grams each.
10. Place pan in the refrigerator to chill the dough for 30 minutes.
11. While dough is chilling, preheat oven to 350 degrees.
12. Line two baking sheets with parchment paper.
13. Place the remaining 1/2 cup of granulated sugar in a small bowl and roll each mound of dough into a ball in the palm of your hands. Roll each ball in the sugar, coating completely.
14. Place cookie balls 2 1/2 inches apart on prepared pans.
15. If desired, press the tops of the cookies down with the tines of a fork, making a crosshatch design. Or use the bottom of a measuring cup or glass to gently press the cookie dough down so the surface is flat but the cookie is still thick.
16. Bake until light golden brown, about 10-12 minutes.
17. Remove the pan from the oven and allow the cookies to cool for 5 minutes.
18. Use a spatula to transfer the cookies to a wire rack to cool completely.

For Peanut Butter Mousse

1. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and cream cheese at medium speed until smooth.
2. Add the peanut butter and mix until combined.
3. Slowly add the confectioner’s sugar in two additions, alternating with the heavy cream.
4. Beat on medium speed until smooth and creamy.
5. Place the mousse into a piping bag fitted with a large star tip.
6. Pipe a swirl of peanut butter mousse onto the flat side of one cookie and then top with another cookie.
7. Refrigerate the assembled sandwich cookies for about 30-45 minutes until the filling is set.