*Note: the recipe calls for cake flour, which I never have on hand so I substituted 2 3/4 cups plus 1 tablespoon all-purpose flour and 3 tablespoons cornstarch for the three cups of flour called for in the recipe. It worked beautifully.
*Makes enough for two 9-inch layer cakes (bake according to recipe), or one 9X13-inch cake (bake for 30 to 35 minutes), or one 12-cup bundt pan (bake for 40 to 45 minutes), or 24 cupcakes (bake for 18 to 20 minutes)
Process sugar, flours (or flour and cornstarch if making the substitution for the cake flour), milk powder, baking powder, and salt in a food processor for 15 seconds to combine. Add butter and vanilla and pulse until the mixture resembles coarse meal (you want this much finer than, say, a pie crust). Freeze the dry mixture in a zipper-lock bag for up to 2 months or use immediately.
To make the cake, adjust an oven rack to the middle position and preheat the oven to 350 degrees. Grease and flour your pan of choice (see the note above the recipe).
With an electric mixer, beat the prepared cake mix, 1 1/4 cups warm water and 2 large room-temperature eggs until the mixture is smooth, about 2 minutes. Scrape the batter into the prepared cake pan(s) and bake until a toothpick inserted in the center comes out clean, about 25-27 minutes for two 9-inch layer cakes. See the note above the recipe for alternate cooking times with other baking pans. Cool the cake(s) in pan(s) for 10 minutes, then turn out onto a wire rack. Cool completely.
Recipe Source: adapted slightly from Cook’s Country April/May 2010