Pre-heat oven to 325º F (static) or 300º F (convection).
Spray or oil two 8-inch round cake pans with non-stick cooking spray and dust entire surface lightly with gfJules Flour (line bottom with parchment paper, if desired). To make cupcakes, oil or line cupcake pans with cupcake papers (Makes approximately 28 cupcakes).
Whisk together the flour, powdered milk/pudding mix, baking powder and salt and set aside.
In a large mixing bowl, combine the butter and sugar and beat well with your mixer’s paddle attachment, until the mixture is very light and fluffy (approximately 3-4 minutes). Add the eggs next, one at a time (or egg subs noted below) beating well after each addition. Mix in the vanilla with the last egg addition.
Slowly add the milk, alternating with the flour mixture and beating in between the additions. Beat until smooth and pour into the prepared pans.
Allow cakes to sit in the pan for 15 minutes before baking. For cakes, bake for 40 minutes, turning the pans half-way through if using convection setting; for cupcakes, test after 20 minutes for doneness.
To test the cakes for doneness, insert a cake tester or toothpick in the middle of each cake and be sure it comes out clean, with very few crumbs attached. The cakes will also begin to pull away slightly from the sides of the pans. Add time if necessary to fully bake the cakes.
When done, turn off the oven and leave the oven door open to let the cakes cool slowly there for 5 minutes or so, then remove the cakes to a cooling rack. After 15-20 minutes of total cooling time, gently invert the cakes to remove them from the pans, then flip gently back onto the cooling rack until fully cooled.
Frost the cakes only when fully cooled, or in the alternative, you may wrap the cakes with wax paper or plastic wrap and seal inside freezer bags to freeze or refrigerate until ready to use.