This super easy to make, moist, and fluffy Vanilla Tray Bake is topped with creamy vanilla buttercream frosting and is absolutely perfect for finishing with your favorite sprinkles! Bake this delicious and tender cake for a birthday cake, a family dessert, or anytime you need a classic vanilla cake that can feed a crowd!
Preheat your oven to 350 degrees F (175 degrees C) and grease and flour your 9 x 13 baking pan or spray with non-stick baking spray. *Parchment paper sheets can also be used for ease of lifting the tray bake out of the pan in one piece.
In a large mixing bowl, or the bowl of your stand mixer, sift the dry ingredients including the cake flour (or substitute in the notes below), sugar, baking powder, and salt. Whisk the dry ingredients together.
Cut the cubed butter into the flour mixture at medium speed, or using a pastry cutter, or a pair of knives cut in a crisscrossed motion, until the butter is small pieces that are about pea-size.
Add the eggs and vanilla extract, then continue mixing at medium speed until the dry ingredients are just incorporated. Add the milk in two half-cup portions, slowly adding the first portion. Mix until the batter is smooth, then add the second half-cup portion of milk and mix until smooth.
Transfer your batter to the prepared 9 x 13 baking pan. Bake at 350 degrees F (175 degrees C) for 25-30 minutes, checking at the 25 minute point of baking. The top of the cake should spring back from the touch, and an inserted knife or toothpick should come out clean when done.
Remove the baked cake from the oven and allow to cool completely in the pan, placed on a wire cooling rack. The cake needs to cool for at least 30 minutes before frosting.
Vanilla Buttercream Frosting
In a large mixing bowl (with a hand mixer), or the bowl of your stand mixer (with the paddle attachment), start beating the slightly softened butter at a medium speed.
Add 4 ½ cups confectioner sugar, ¼ cup heavy cream, and a tablespoon of vanilla extract. Beat on low speed for about a minute (or until the confectioner's sugar won't blow out of the bowl) before increasing the speed to medium-high. Beat until smooth and creamy, about 2 minutes.
Depending on your desired frosting consistency (smooth for spreading, or firmer for piping) adjust the frosting thickness as needed. Add the additional confectioner's sugar if the frosting is too thin, or add a drizzle more of heavy cream to thin the frosting out. Taste and add a pinch of salt to balance the sweetness as needed.
Once the vanilla cake is cooled, spread the frosting using an offset spatula to cover the cake. Or use a piping nozzle to decorate the cake and top with sprinkles if desired.
If you don't have cake flour, you can measure out 1 cup all-purpose flour and either 1) remove 2 tablespoons of the flour or 2) remove 2 tablespoons of the all-purpose flour and add 2 tablespoons of cornstarch (or arrowroot powder). Sift to combine the cornstarch and flour.