With an electric mixer, cream butter and sugars in a small mixing
bowl. Add vanilla and egg; cream again until smooth. Add the flour,
baking soda, and salt. Stir gently until incorporated. Stir in
chocolate chips. Store in refrigerator until ready to use.
Preheat oven to 350 degrees. Prepare brownie batter as directed.
Pour batter into a glass 8×8 or 9×9 baking dish. Scatter pieces of
cookie dough over the top of the brownie batter. Press gently on
the dough just until it starts to sink down into the batter a little bit.
Bake for 35-40 minutes (35 for gooey, 40 or more for fully baked),
covering with foil if you need to keep the cookies from getting too
brown on top. Let stand for 15-20 minutes and cut into pieces for