Remove 1 pouch Krusteaz Professional Ready to Bake Sweet Cream Vanilla Cake & Muffin batter from refrigerator. No slacking required.
Prepare 16x12x1-inch half-sheet pan by lightly greasing, lining with parchment paper and then lightly greasing the parchment paper. If using a pan extender (recommended), lightly grease the sides of the pan extender.
Cut open one end of the pouch and squeeze all of batter into prepared pan and spread evenly.
For convection oven, bake at 300°F at low fan speed for 25-30 minutes, turning pan halfway through bake time. Allow cake to cool completely before cutting or removing from pan.
For filling: place Krusteaz Professional Vanilla Crème Icing mix in mixer bowl. Using a paddle, gradually add hot water while mixing on low speed 1 minute. Add melted butter and mix 1 minute. Scrape bowl and paddle. Change to high speed and mix until light and creamy.
For assembly: Using a serrated knife, cut cooled sheet cake into 4 16x3-inch rectangles. Place one rectangle on platter/cutting board. Spread vanilla buttercream on top of layer. Top with a layer of sliced peaches. Place second layer on top of peaches, pressing down gently.
Repeat process for 2nd cake with other 2 layers. Chill to set buttercream before cutting into serving slices.