Preheat your oven to 350°F (175°C). In a large mixing bowl, combine the graham cracker crumbs and melted butter until fully mixed. Press this mixture into the bottom of a 9x13 inch baking dish. Bake for 8 to 10 minutes until lightly golden, then let it cool completely.
In a separate mixing bowl, beat the softened cream cheese and granulated sugar together until smooth. Add the vanilla extract and mix until well incorporated.
In a clean bowl, whip the heavy whipping cream until soft peaks form. Gradually add the powdered sugar while continuing to whip until stiff peaks are achieved.
Gently fold the whipped cream into the cream cheese mixture until well combined.
Spread half of the chocolate cream mixture evenly over the cooled graham cracker crust.
Sprinkle a layer of semi-sweet chocolate chips over the chocolate cream mixture, then add the crushed nuts.
Spread the remaining chocolate cream mixture over the chocolate chip and nut layer.
Top with another layer of semi-sweet chocolate chips and crushed nuts, then drizzle with chocolate syrup and optionally dust with cocoa powder.
Cover the dish with plastic wrap and refrigerate for at least 4 hours or overnight.
Once chilled, cut the Cookie Lasagna into squares and serve.
Notes
Allow your Cookie Lasagna to chill for at least 4 hours for best texture and flavor. Customize with different nuts or toppings as desired.