Salted Caramel Peanut Brownie Bars

Preparation

1. Step 1

   Heat oven to 350 degrees. Line a 9-inch square pan with parchment, leaving a 2-inch overhang on two sides.

2. Step 2

   Prepare the base: In a medium bowl, whisk together flour, cocoa, salt and baking soda. In a large bowl, or in the bowl of a stand mixer fitted with the paddle attachment, beat together the butter, granulated sugar and brown sugar until creamy, 1 minute. Add the egg and vanilla and beat until combined. Mix in the flour mixture and the chocolate until evenly moistened.

3. Step 3

   Transfer the thick batter to the prepared pan and spread it out into an even layer with an offset spatula. Bake until the base looks dry and set, about 25 to 30 minutes. Transfer to a rack to cool.

4. Step 4

   Prepare the topping: To a small saucepan with high sides add ¼ cup/60 milliliters water. Pour the sugar and corn syrup into the center of the pan. Bring to a simmer over medium-high heat and cook until the mixture is a medium amber color, about 15 minutes, swirling the pan occasionally. Quickly and carefully add the cream and the butter. Take care: The mixture will steam and sputter. Stir the mixture until combined and clip a candy thermometer to the side of the pot.

5. Step 5

   Cook the caramel until the mixture reaches 238 degrees, about 5 to 10 minutes. Remove from the heat and stir in the peanuts and the kosher salt. Pour the caramel over the base, using the raised edges of the base that formed while baking to keep the caramel on top. Sprinkle with flaky salt. Let stand until the caramel is completely cool.

6. Step 6

   Using the parchment overhang, transfer the bar to a cutting board. Cut into 32 small rectangles to serve.