Peanut Brown-Butter Cookies

Preparation

1. Step 1

   Prepare the cookies: In a small saucepan over medium heat, melt the butter. When it starts to bubble, lower the heat to medium-low and cook, stirring constantly with a spatula, until the butter browns, 4 to 5 minutes. Transfer, scraping up the butter solids, into a small bowl and set aside to cool to room temperature.

2. Step 2

   Once the butter is cooled, scrape it into the bowl of a stand mixer fitted with a paddle attachment. (Or move it to a large bowl and use a hand mixer.) Add the dark brown sugar and peanut butter, and beat on medium speed until the mixture is pale, 2 to 3 minutes. Scrape down the sides of the bowl, and add the egg and vanilla extract. Beat again until the mixture is smooth and creamy, 1 minute. Add the flour, salt and baking soda, and mix on low until combined, scraping the bottom as you go.

3. Step 3

   Arrange the racks in the top and bottom thirds of the oven. Heat oven to 350 degrees. Line 2 baking sheets with parchment paper.

4. Step 4

   Roll the dough into roughly 1½-tablespoon-size balls and place them on a plate.

5. Step 5

   Prepare the coating: Beat the remaining egg with 1 tablespoon water in a small bowl. Spread the chopped peanuts on a large plate.

6. Step 6

   Dip each dough ball into the egg mixture and roll and press the peanuts into each ball. (Use some pressure to make sure the peanuts really stick. The dough may crack slightly when pressed, and that is fine. Just add peanuts into the cracks.) Space the dough balls about 1 inch apart on the prepared baking sheets, and, using your hand, press them gently until they’re ½-inch thick. Sprinkle each with flaky sea salt.

7. Step 7

   Bake the cookies until they are golden brown on the edges, 13 to 14 minutes. Remove from the oven and cool on a rack before serving.