Step 1: Preheat Your Oven - Start by preheating your oven to 350°F (175°C). This ensures your bars bake evenly and develop a perfect golden crust.
Step 2: Prepare the Baking Pan - Line your 9x13 inch baking pan with parchment paper, allowing some overhang on the sides. This will make it super easy to lift the bars out later.
Step 3: Press the Cookie Dough - Take your chocolate chip cookie dough and press it evenly into the bottom of the prepared baking pan. Use your hands or a spatula to ensure it's an even layer.
Step 4: Bake the Cookie Base - Place the pan in the preheated oven and bake for about 10-12 minutes, or until the edges are lightly golden. Remove the pan from the oven and let it cool slightly.
Step 5: Layer the Toppings - Once the cookie base is slightly cooled, sprinkle the white chocolate chips, semi-sweet or milk chocolate chips, toffee bits, and chopped nuts evenly over the cookie dough.
Step 6: Drizzle with Sweetened Condensed Milk - Pour the sweetened condensed milk evenly over the entire layer of toppings. This will bind everything together as it bakes and creates that magical gooey texture.
Step 7: Bake Again - Return the pan to the oven and bake for an additional 20-25 minutes, or until the top is golden and bubbly. The edges might be slightly crispy, which is perfect!
Step 8: Cool and Cut - Once baked, remove the pan from the oven and allow it to cool completely in the pan. Once cooled, use the parchment overhang to lift the bars out. Cut into squares and enjoy!