These decadent cookie bars combine a buttery shortbread crust, a layer of chewy chocolate chip cookie dough, and a topping of chopped candy bars for an irresistible treat that's perfect for parties or bake sales.
Preheat oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving overhang on two sides.
In a large bowl, beat butter, granulated sugar, and brown sugar until light and fluffy. Add eggs one at a time, then vanilla, beating well after each.
In a separate bowl, whisk flour, baking soda, and salt. Gradually add to butter mixture, mixing until just combined. Fold in chocolate chips.
Press half of the cookie dough evenly into the prepared pan. Sprinkle chopped candy bars over the dough. Drop remaining dough by spoonfuls over the candy bars and gently spread to cover (it's okay if some candy shows).
Bake for 25-30 minutes, until golden brown and edges are set. Cool completely in pan on a wire rack.
Use parchment overhang to lift bars from pan. Cut into 24 squares.
Tips
For easier cutting, chill the bars for 30 minutes after cooling.
Store in an airtight container at room temperature for up to 5 days.
Freeze bars for up to 3 months; thaw at room temperature before serving.