• Preheat oven to 350 degrees and grease three 9" cake pans with cooking spray.

Cake

• Beat butter and cake mix with a mixer (the batter will be thick). Add in eggs, one at a time, beating well after each addition. Add in milk, espresso powder, and vanilla extract; mix until combined.
• Divide batter evenly between two cake pans.
• Bake for 27-30 minutes, or until a cake tester comes out clean.

Cookie

• Beat butter and cookie mix until combined. Add in egg and beat until combined.
• Press cookie dough in an even layer into one cake pan.
• Bake for 20-21 minutes, or until just golden brown on top.

Filling

• Beat heavy cream until stiff peaks form.
• Place bottom cake layer onto a cake stand. Spread with 3 Tbsp of chocolate-hazelnut spread, making sure to leave 1/4" border around the sides of the cake. Top with 3/4 cup of whipped cream, also leaving a 1/4" border around the sides of the cake (when the cookie layer is added, the weight will push the filling to the edges). Add 2 Tbsp crushed cookie crumbs on top of the cream.
• Place the cookie layer on top, and repeat the filling steps above.
• Place the final layer of chocolate cake on top.

Frosting

• Beat frosting mix with butter (mixture will be thick). Slowly pour in water and vanilla, and beat until well combined.
• Spread frosting over the top and sides of the cake.

Topping

• With the remaining 1/2 cup of cream, pipe dollops of whipped cream around the top of the cake.
• If desired, top with cookie crumbs.
• Enjoy!