In a small saucepan place granulated sugar and 1/3 cup water. Set a medium heat and bring to a boil, stirring occasionally. Remove from heat when sugar has dissolved, add amaretto, if using, and almond extract. Allow syrup to cool.
Slice the two cake layers in half horizontally using a serrated knife, forming four layers. Crumble one into the bowl; process until fine crumbs form
Liberally brush tops of remaining three cake layers with cooled syrup. Rest one cake layer on a 6-inch cardboard cake round.
Keep the ice cream in the refrigerated bowl of an electric mixer fitted with paddle attachment. Beat on intermediate-low speed until spreadable for 2 minutes. Add 2 cups ice cream over first cake layer. Spread 1/2 cup almond crunch over ice cream. Cover with a second cake layer. Move cake and ice cream to freezer until stiff for 10 minutes
Eradicate cake and ice cream from freezer. Add 2 cups ice cream over top. Spread 1/2 cup almond crunch over ice cream. Keep the third cake layer on top. Add 2 cups ice cream over cake layer. Keep the cake and ice cream in freezer for 30 minutes.
Eradicate cake and ice cream from freezer; mix the left out ice cream with rubber spatula to resoften. With an icing spatula rapidly spread remaining 2 cups ice cream around sides of cake. Then again move the cake to freezer for 30 minutes.
In a chilled bowl, whisk cream and confectioners' sugar with a hand mixer until soft peaks form. Eradicate cake from freezer; frost top and sides of cake with whipped cream. Pat reserved crumbs onto sides of cake, and crumble left out cup almond crunch over the top. Keep the cake in freezer; freeze until totally hardened, at least 2 hours