Turn off mixer, add powdered sugar and salt and whisk on low for 15 seconds, then on medium-high 2-3 minutes or until smooth, creamy and fluffy.
If baking a cake, this recipe makes one 13x9-inch cake. Adjust the oven rack to the middle position. Spray a 13 x 9-inch baking pan with cooking spray. Line the bottom only of the pan with parchment paper then also spray the parchment.
Bake the cake 35-40 minutes – be sure to rotate the pan halfway through baking.
Cool the cake on a cooling rack.
*If adding nuts and/or raisins, the cake will need an additional 5-10 minutes baking time in the oven.
These cupcakes freeze beautifully, but freeze without the frosting. Wrapped in plastic wrap, place in a freezer container and wrap the whole thin in aluminum foil twice. When ready to serve, remove from the freezer and let warm to room temperature while still wrapped. Add the frosting once they come room temperature.