Ingredients
Scale
Cookies
- 1 ½ cups all-purpose flour
- 2 teaspoons baking soda
- ¾ teaspoon baking powder
- 1 ½ sticks unsalted butter room temperature
- ½ cup packed light brown sugar
- 1/3 cup creamy peanut butter (I used Skippy)
- 1 tablespoon pure vanilla extract
- 1 large egg
- 1 1/3 cup old fashioned rolled oats
- ¼ cup peanuts, finely chopped (I used Planter’s Dry Roasted Unsalted)
Filling
- 4 large egg whites
- ½ teaspoon cream of tartar
- 1 cup granulated sugar
- ¼ cup water
- 6 tablespoons unsalted butter, room temperature, cut into pieces
- ¾ cup creamy peanut butter (I used Skippy)
- ¼ teaspoon kosher salt, optional
Instructions
- Make the cookies. Preheat oven to 325 degrees F. Line 3 sheet pans with parchment.
- In a medium bowl, stir together flour, baking soda, and baking powder. In a large bowl, mix together butter, sugar, peanut butter, and vanilla until light and fluffy. I did this by hand, but a hand or stand mixer would work as well. Mix in the egg until fully combined. Stir in the dry ingredients until just combined. Stir in oats and peanuts. Using a small ice cream scoop, scoop dough onto prepared pans. Bake about 14 minutes, rotating halfway through if necessary, until cookies are light golden brown and mostly set. Cool completely on pans.
- Make the filling. Place the egg whites in the bowl of a stand mixer fitted with the whisk attachment. Beat on medium-high until foamy. Add the cream of tartar and beat until stiff peaks form. In the meantime, in a medium saucepan, stir sugar and water together over medium heat until the sugar has dissolved. Once the sugar is dissolved, stop stirring and attach a candy thermometer to the side of the pan. Continue cooking the sugar until it reaches 248 degrees F on the thermometer. This happens quickly, so make sure the egg whites are about ready before cooking the syrup. Once the whites reach stiff peaks, they can be turned off for a few moments while the syrup cooks. Turn them back on medium high for about 30 seconds before adding the syrup.
- Once the syrup and whites are ready, turn the mixer to low and slowly drizzle in the syrup. When all the syrup is added, turn the mixer back up to medium high and beat until sticky, fluffy, voluminous, and room temperature, about 15 minutes. Add butter a couple pieces at a time with the mixer running. Beat until the filling is smooth and creamy. Measure 1 ¼ cups of the filling and place in a separate bowl. What’s left in the stand mixer bowl should be reserved for another use. (May I recommend eating with a spoon!) Add the peanut butter and salt, if using, to the 1 ¼ cups of filling and stir until fully combined.
- Spread a generous amount of filling on top of one cookie with an offset spatula and top with another cookie. Repeat until all the sandwiches have been made. Cookies may be stored in the refrigerator in an airtight container for up to 3 days or frozen, wrapped in parchment and foil and placed in a zipper bag, for up to 4 months. Thaw at room temperature for about an hour.
Notes
Recipe adapted from Thomas Keller, courtesy of Saveur
- Prep Time: 1 hour
- Cook Time: 40 minutes