Black-Bottom Cookie Bars
from Tasty Kitchen
225g unsalted butter, melted, plus more for greasing.
1 cup packed light brown sugar
1/2 cup caster sugar
2 large eggs, lightly beaten
1 1/2 teaspoons vanilla extract
2 cups plain flour
1/2 teaspoon salt
1/4 cup cocoa powder
1 1/4 cups dark chocolate chips
Preheat oven to 180 degrees C. Lightly butter a 20cm square baking pan. Line with baking paper, leaving some to overhang on two sides. Lightly butter the paper.
With an electric mixer with the whisk attached, whisk together butter and both sugars. Whisk in eggs and vanilla. Turn the speed down to low and gradually add flour and salt, mixing just until combine.
Divide batter in half, and transfer one half to a separate bowl. Stir in cocoa powder and chocolate chips until combined.
Place chocolate batter in baking pan. Spread evenly and smooth top. Spread plain batter on top of chocolate batter. Smooth top.
Bake 25-30 minutes, or until top is golden brown and a toothpick inserted in the center comes out clean. Cool completely in pan on wire rack before cutting. (I cut mine while they were still a tad warm. The kettle was on and I couldn't wait okay? I know you find that hard to believe.)