Spray a loaf pan with nonstick cooking spray then line with plastic wrap.
Start with the banana, laying the slices in the bottom of the loaf pan to create a full single layer.This will be the top of your cake.A large scoops of softened strawberry ice cream on top and smooth. You will likely only need about 1 1/2 pints of each flavor. Another layer of banana slices on top, then create a layer of Nilla wafers. Freeze for about 2 hours, or until the ice cream is firm again.
When the ice cream is set, dollop large scoops of softened chocolate ice cream on top and smooth with an offset spatula. Add another layer of banana slices and finish with a layer of Oreos, to create a chocolate cookie crust. You may need to halve some Oreos to completely cover the bottom. Cover the cake with plastic wrap and freeze for another 2 hours, or until the ice cream hardens.
When the ice cream is set, run a knife around the plastic wrap to loosen the cake, and invert the cake onto a serving platter. Remove the plastic wrap. Garnish with chocolate syrup, whipped cream, walnuts, sprinkles and maraschino cherries. Slice crosswise and enjoy