Preheat oven to 350 degrees. Spray the bottom of a 9 inch springform pan with non-stick spray.

Melt butter in a skillet over medium-low heat. Once melted, mix in cocoa powder. Allow to cool 10 minutes.

Whisk sugar into cocoa mixture. Whisk in eggs one at a time. Whisk in vanilla.

In another bowl combine flour, baking powder and salt. Slowly whisk into the cocoa mixture. Fold in crushed cookies.

Spoon batter into prepared baking pan. Bake for 20 - 25 minutes or until a toothpick inserted comes out with just a few crumbs on it.

Remove from oven and allow to cool completely.

While cooling, place ice cream on the counter for 20 minutes to soften.

Spread softened ice cream over brownies. Top with marshmallows and graham crackers. Place in the freezer until frozen, at least 4 hours or overnight.

Carefully remove the outer ring of the springform pan.

To make the ganache, heat heavy cream in the microwave for 30 seconds or just until steaming. Stir in chocolate chips. Allow to set for 1 minutes. Begin stirring and stir until smooth and shiny.

Drizzle ganache over the cake, slice and serve.