Instructions

To make the peanut butter filling

1. In a small bowl, beat the peanut butter, powdered sugar, and vanilla until smooth.

To make the cookies

1. Preheat the oven to 350 degrees Fahrenheit and line a cookie sheet with parchment paper.
2. In a medium mixing bowl, whisk together the flour, cocoa, and salt. Set aside.
3. In a large mixing bowl, beat together the butter and sugar until light and creamy. Add the egg yolk and vanilla, and beat to combine. Add the dry ingredients and beat on low until the dough just comes together, about one minute.
4. Use a medium cookie scoop to scoop the dough into balls and drop them two inches apart on the cookie sheet. Flatten the tops of the dough balls.
5. Use the back of a 1/2 teaspoon to made an indentation in the center of each dough ball.
6. Scoop one teaspoon of the peanut butter mixture, roll it into a ball, and press into the indentation. Repeat with all cookies.
7. Bake cookies for 15 minutes, until the edges are firm to the touch.
8. Let cookies rest for 5 minutes before transferring to wire racks to cool completely.
9. Put the chocolate in a small microwave-safe bowl. Melt by heating in 30-second increments, stirring in between each interval until the chocolate is perfectly smooth.
10. When the cookies are cool, use a spoon to drizzle the chocolate over the tops of the cookies.