01 -
Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat. Place 1/2 cup granulated sugar in a small bowl and set aside.
02 -
Whisk together all-purpose flour, baking soda, and kosher salt in a medium bowl. Set aside.
03 -
In a large mixing bowl, cream unsalted butter, light brown sugar, and creamy peanut butter using a stand mixer or electric hand mixer until smooth and airy.
04 -
Add large egg and vanilla extract, continuing to mix until fully blended.
05 -
Gradually mix dry ingredients into the wet mixture on low speed, just until a uniform dough forms.
06 -
Scoop dough by tablespoon, roll each portion into a ball, then shape into logs. Roll each log in reserved sugar to coat evenly.
07 -
Place logs on prepared baking sheet, spacing evenly. Bake for 10 minutes or until edges are lightly golden. Cool cookies completely on a wire rack.
08 -
Using a stand mixer, beat softened butter and peanut butter on medium speed until fluffy. Add powdered sugar, milk, and vanilla extract. Beat until smooth and creamy.
09 -
Spread prepared filling on the flat side of one cooled cookie, then top with a second cookie to create a sandwich. Repeat with remaining cookies.