Preheat the oven to 350°F (175°C). Grease and flour a 9×13 inch baking pan.
In a large bowl, combine the yellow cake mix, water, vegetable oil, and eggs. Beat with an electric mixer on medium speed for 2 minutes.
Pour the batter into the prepared baking pan and bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and allow it to cool completely in the pan on a wire rack.
While the cake is baking, prepare the banana pudding. In a medium bowl, whisk together the instant banana pudding mix and cold milk until thickened. Refrigerate until ready to use.
Prepare the strawberry Jello by dissolving the Jello powder in 1 cup boiling water. Stir until completely dissolved, then add 1 cup cold water. Refrigerate until slightly thickened but not set, about 30 minutes.
Once the cake has cooled, poke holes all over the top of the cake using the handle of a wooden spoon or a fork.
Pour the slightly thickened strawberry Jello evenly over the cake, allowing it to seep into the holes. Refrigerate the cake for 1 hour to set the Jello.
After the Jello has set, spread the prepared banana pudding evenly over the top of the cake.
Arrange the sliced bananas evenly over the banana pudding layer.
In a chilled mixing bowl, beat the heavy whipping cream, powdered sugar, and vanilla extract on high speed until stiff peaks form.
Spread the whipped cream evenly over the banana layer.
Decorate the top of the cake with maraschino cherries, placing one cherry on each slice if desired.
Refrigerate the cake for at least 2 hours before serving to allow all layers to set and flavors to meld.