Peanut Butter Cookie Bars

01Method

1. 1

   For the peanut butter cookie base: Heat the oven to 350°F and position a rack in the centre. Grease a 9×9-inch baking dish with butter.

2. 2

   In a medium bowl, whisk together the flour, baking soda, and salt until evenly combined.

3. 3

   In a separate medium bowl, beat the butter, peanut butter, and brown sugar with a hand mixer until smooth and creamy, about 2 minutes. Mix in the egg thoroughly, then add the dry mixture and beat until just incorporated. Using lightly floured hands, press the dough evenly into the prepared dish. Bake until golden at the edges, 15 to 18 minutes. Transfer to a wire rack and allow to cool completely.

4. 4

   For the chocolate sour cream frosting: Put the chocolate chips in a heatproof bowl and microwave in 30-second bursts, stirring between each, until fully melted. Set aside to cool slightly.

5. 5

   Using a hand mixer, beat the butter until pale and fluffy. With the mixer on low, incorporate the confectioners' sugar in stages, beating until the mixture is completely smooth. Add the melted chocolate and sour cream and mix until uniform.

6. 6

   To assemble: Spread the frosting in an even layer over the cooled cookie base. Scatter the crushed peanut butter candies, potato chips, and pretzel pieces over the top. Cut into 16 bars and lift them out with a small offset spatula.