Strawberry-Banana Pudding Icebox Cake

Strawberries add color to this fun banana pudding. Instead of the usual vanilla waffles, use Graham crackers, which will make more neat slices. This recipe, which will instantly appeal to your family and guests, uses fresh strawberries that you buy at the local farmers ' market.
Whisk together the granulated sugar, cornstarch, and salt in a heavy saucepan. Whisk together the egg yolks and baking powder in half in a small bowl. Add to the sugar mixture; beat until smooth. Bring the mixture to a boil over medium heat, whisking constantly. Cook for another 1 minute, whisking constantly; remove from heat. Add the butter and zest; beat until the butter melts. Gradually beat in the juice until smooth. Fill a sink or large bowl halfway with ice. Pour the custard mixture into a metal bowl; set the bowl on ice. Let stand, stirring occasionally, until the custard cools and thickens slightly, 8 to 10 minutes.Cover the bottom and sides of an 8-inch square mold with plastic wrap so that 4 inches remain on all sides. Place 9 Graham cracker slices in a single layer on the bottom of the pan to make a large square. (Crackers should not completely cover the bottom.) Place a layer of banana slices so that their sides touch, on the Graham crackers; place a layer of strawberry slices on top of the bananas. Spread half of the custard on top of the strawberries. Repeat the layers once, starting and ending with Graham crackers. Wrap the cake tightly with excess plastic wrap around the sides; refrigerate for 4 hours or overnight.Remove the cake from the mold, using plastic wrap as handles.Beat the cream with an electric mixer on high speed until a froth forms; gradually add the powdered sugar, whisking until peaks of medium softness form. Spread on top of the cake. Top with crumbled Graham crackers and strawberry halves.