Classic Vanilla Butter Cake

Ingredients

• For the cake:
• 16 ounces plain or toasted sugar
• 4 1/2 teaspoons baking powder
• 2 teaspoons Diamond Crystal kosher salt; for table salt, use about half as much by volume or the same weight
• 8 ounces unsalted butter, soft but cool, about 60°F
• 3 large eggs, brought to about 65°F
• 1/2 ounce vanilla extract
• 16 ounces whole milk, brought to about 65°F
• 16 ounces all-purpose flour
• To Finish:
• 1 recipe Swiss Buttercream

Directions

1. For the Cake: Move an oven rack to the lower-middle spot, then heat the oven to 350 degrees F (180 degrees C). Lightly grease 3 8-inch anodized aluminum cake pans and line them with parchment. If you only have fewer pans, bake in rounds; the extra batter can wait at room temperature until its turn.
2. In the bowl of a stand mixer with the paddle attached, add the sugar, baking powder, salt, and butter. Start on low just to bring everything together, then turn the mixer to medium and beat until the mixture looks pale and fluffy, about 5 minutes. Midway through, stop and use a flexible spatula to clear the bowl and paddle.
3. Keep the mixer going and add the eggs 1 at a time, waiting until each egg disappears into the batter before the next goes in, then slowly pour in the vanilla. Drop the speed to low, add about 1/3 of the flour, and follow with 1/3 of the milk. Continue the same way with the rest of the flour and milk, adding them in 3 parts.
4. Stop to scrape down the bowl and paddle with a flexible spatula, then mix again on medium for about 3 seconds so the batter is completely even. It should be thick and creamy, with a digital thermometer reading between 65 and 68 degrees F (18 and 20 degrees C). If the temperature is far outside that range, the ingredients were likely warmer or colder than ideal, which can affect the cake’s texture.
5. Use a flexible spatula to lift and turn the batter from the bottom 1 or 2 times, then portion it evenly into the prepared pans, about 20 ounces or 565g per pan if you are weighing. Arrange the pans on the oven rack so they are staggered together, and bake until the layers are risen, set, and a light golden color, about 32 minutes. For an oven that bakes unevenly, stop after about 20 minutes to turn the pans. You can also bake two layers first, then bake the third after those come out.
6. Let the cakes rest in their pans for 1 hour. Slide a butter knife along the sides to release them, turn them out onto a wire rack, remove the parchment, and flip the layers upright again. If wrapped in plastic, the cakes can sit at room temperature for a few hours. Prepare the buttercream.
7. For the Crumb Coat: Trim the cake layers level with a serrated knife, saving the scraps for snacking. Set one layer on a heavy cast iron turntable. If you want, place a waxed cardboard cake round beneath it first, anchoring the round to the turntable with a damp paper towel scrap. Spoon exactly 1 cup buttercream on top and spread it evenly to the edges with an offset spatula. Do the same with the second and third layers, then use another 1 cup buttercream to coat the sides, smoothing it as neatly as you can. Chill the cake until the buttercream is firm, about 30 minutes.
8. To Finish: Whip the remaining buttercream again until it is creamy, then decorate and finish the chilled cake however you like. Before serving, let the cake stand at room temperature for at least an hour so the center is not too cold. Slice with a chef’s knife, and use any leftover buttercream to cover the cut edges so the cake stays moist. Kept beneath a cake dome, the cake will hold at room temperature for 3 days.