This recipe is a from-scratch version of boxed cake and frosting that is just as easy as the store-bought version — no mixer required. If you’re the type of person who gets weirded out by food coloring, you can omit it or use natural dye, although I think the blush — or bashful — shade of pink is what makes the cake so fun.
Pink Birthday Sheet Cake
Heat the oven to 325 degrees. Grease a 9-by-13-by-2½-inch metal baking pan with baking spray.
In a large bowl, whisk together the flour, milk powder, cornstarch, baking powder and salt. In a medium bowl, whisk together the sugar, whole milk, oil, vanilla and eggs until smooth. Pour the liquid ingredients over the dry ingredients and whisk until just combined. Pour the batter into the prepared pan and smooth the top. Bake until golden brown on top and a toothpick inserted in the center of the cake comes out clean, 40 to 45 minutes.
While the cake is in the oven, make the frosting: In a large bowl, beat the shortening and butter together with a hand mixer on medium speed until smooth. With the mixer on low speed, slowly spoon the sugar into the fat mixture until completely incorporated and smooth; add 2 tablespoons cream, the vanilla and salt. Slowly add drops of food coloring until it’s the shade of pink you want— go light for a baby pink or heavier for a more magenta hue. Continue mixing until the color is homogeneous; if the frosting seems too thick, add the remaining 1 tablespoon cream so that it is spreadable.
As soon as the cake is ready, remove the pan from the oven and scrape the frosting onto the cake. Use a rubber spatula to quickly spread it evenly over the top as it melts. The frosting will separate into opaque and solid sections, that’s OK; continue spreading it as it melts until it no longer is separated and the frosting forms an even, solid layer on top. Let the cake cool until the frosting becomes a crackly doughnut-like glaze over the cake, then serve while still slightly warm from the pan. This cake is also great served cooled completely to room temperature.