Chocolate Chip Cookie Millionaire Bars

Preheat oven to 350 degrees F (180 degrees C). Gather all ingredients. (5 minutes)

Spray a 13- x 9-inch baking pan with baking spray; line bottom and sides with parchment paper, leaving a 1- to 2-inch overhang on long sides. (5 minutes)

Break apart dough squares along perforations and evenly scatter in bottom of the prepared pan. Let stand at room temperature until softened, 5 to 10 minutes. Using a sheet of plastic wrap placed directly on surface, press dough into an even layer in the bottom of the pan. Remove and discard plastic wrap. (15 minutes)

Bake in the preheated oven until golden brown and a wooden pick inserted in center comes out clean or with just some moist crumbs, 25 to 30 minutes. Let cool in pan on a wire rack while making filling. (30 minutes)

Add condensed milk, brown sugar, corn syrup, salt, and 1 cup of the butter to a large saucepan; cook over medium, whisking constantly, until butter is melted and mixture starts to bubble, about 10 minutes. (10 minutes)

Continue to cook, whisking constantly, over medium until mixture is a caramel color, thickened, and registers 235°F on a candy or instant-read thermometer, about 10 minutes. Remove from heat and stir in vanilla until combined. (10 minutes)

Working quickly, pour caramel over cookie layer, spreading into an even layer with a small offset spatula. Chill in refrigerator, uncovered, until set, about 1 hour. (1 hour)

Add chocolate, cream, and remaining 2 tablespoons butter to a medium, heatproof bowl; place bowl over a saucepan filled with 1 inch of simmering water, making sure bottom of bowl does not touch water. Cook, stirring constantly, until chocolate mixture is melted and smooth, 2 to 3 minutes. (3 minutes)

Working quickly, pour and spread chocolate mixture evenly over caramel layer. Chill in refrigerator, uncovered, until set, about 1 hour. (1 hour)

Using parchment paper as handles, remove from pan and place on a cutting board. Using a warm, dry, sharp knife, cut into bars; wipe knife clean with a damp paper towel between cuts, if desired. Serve immediately or store in an airtight container at room temperature for 3 to 5 days. (5 minutes)