Coffee and Fudge Ice Cream Cake

1. To make the fudge sauce: Combine the cocoa powder, cream, honey, sugar, and butter in a medium saucepan set over medium heat. Cook, stirring constantly for 5 minutes, or until the butter and chocolate are melted and the sauce is smooth. Remove from heat, stir in the vanilla, and a pinch of salt. Let cool for 10 minutes. 
2. Line an 8-inch square baking pan with parchment paper.
3. Press the chocolate ice cream into the bottom of the pan, top with a layer of graham crackers, then about 1/3 cup of fudge sauce. Freeze 15 to 30 minutes.  Remove from the freezer, add the coffee ice cream, another layer of graham crackers, and then 1/3 cup fudge sauce. Freeze 15 to 30 minutes. Remove from the freezer, add the vanilla ice cream, and then the final layer of graham crackers. Cover and freeze for 6 hours or overnight. 
4. Keep the remaining fudge sauce in the fridge. 
5. When ready to serve, warm the fudge sauce for 30 seconds to 1 minute. Run a knife around the edges of the cake to loosen, then invert the cake onto a platter and remove the paper. Pour the fudge sauce over cake and freeze 5 minutes. 
6. Meanwhile, whip the cream and sugar with an electric mixer until soft peaks form. Dollop the cream over the cake. If desired dust with cocoa powder. Slice and serve immediately.