• Preheat oven according to cake mix instructions.
• Combine cake mix, Sprite and egg white in a blender and mix until combined.
• Pour into cake pan, then bake according to cake mix instructions.
• When baked through, take out from oven and let cool for about 30 minutes.
• While cake is cooling, pour JELL-O mix into a medium bowl, add in boiling water, then stir for about 2 minutes.
• Add in cold water and stir until combined.
• Once cake is cooled, poke holes into the top of the cake with a fork (about every 1/4 inches).
• Pour JELL-O Mixture over the cake, then refrigerate for a couple of hours.

For Whipped Topping

• Once cake is almost done chilling, start on the whipped topping.
• Pour whipping cream into a mixer with the whisk attachment.
• Beat on high until whipping cream creates "peaks" (about 3-4 minutes).
• Add in Marshmallow cream and sugar, then mix until it's smooth.
• Take the cake out of the refrigerator and spread whipped topping over the top.
• Pour a layer of sprinkles on top of the cake, decorate with some Peeps and serve!