For the Cake: Adjust oven rack to lower-middle position and preheat to 350°F (180°C). Lightly grease three 8-inch anodized aluminum cake pans and line with parchment (explanation and tutorial here ). If you dont have 3 pans, its okay to bake the cakes in stages, the batter will keep at room temperature until needed.

In the bowl of a stand mixer fitted with the paddle attachment, combine sugar, baking powder, salt, and butter. Mix on low speed to roughly incorporate, then increase to medium and beat until fluffy and light, about 5 minutes. About halfway through, scrape the bowl and beater with a flexible spatula.

With the mixer still running, add the eggs one at a time, letting each fully incorporate before adding the next, then dribble in the vanilla. Reduce speed to low and sprinkle in about 1/3 of the flour, then drizzle in 1/3 of the milk. Repeat with remaining flour and milk, working in thirds as before.

Scrape the bowl and beater with a flexible spatula, and resume mixing on medium speed for about 3 seconds to ensure everything is well combined. The batter should look creamy and thick, registering between 65 and 68°F on a digital thermometer. (Significant deviation indicates ingredients were too warm or too cold, which can lead to textural problems with the cake.)

Fold batter once or twice from the bottom up with a flexible spatula, then divide evenly between prepared cake pans (about 20 ounces or 565g if you have a scale). Stagger pans together on the oven rack, and bake until puffed, firm, and pale gold, about 32 minutes. If your oven has very uneven heat, pause to rotate the pans after about 20 minutes. Alternatively, bake 2 layers at once and finish the third when theyre done.

Cool cakes directly in their pans for 1 hour, then run a butter knife around the edges to loosen. Invert onto a wire rack, peel off the parchment, and return cakes right-side-up (covered in plastic, the cakes can be left at room temperature for a few hours). Prepare the buttercream.

For the Crumb Coat: Level cakes with a serrated knife (full directions here ) and set the scraps aside for snacking. Place one layer on a heavy cast iron turntable. If you like, a waxed cardboard cake round can first be placed underneath, secured to the turntable with a scrap of damp paper towel. Top with exactly 1 cup buttercream, using an offset spatula to spread it evenly from edge to edge. Repeat with the second and third layers, then cover the sides of the cake with another cup of buttercream, spreading it as smoothly as you can (tutorial here ). Refrigerate cake until the buttercream hardens, about 30 minutes.

To Finish: Rewhip remaining buttercream to restore its creamy consistency, then use to finish and decorate the chilled cake as desired. Let the cake sit at room temperature for at least an hour before serving, otherwise it will be too cold inside. Cut with a chefs knife to serve, and cover the exposed edges with leftover buttercream to keep the cake moist. Under a cake dome, the cake will keep for 3 days at room temperature.

Quick-Toasted Sugar By Stella Parks (alternative to large batch) Use a heavy 10- or 12-inch skillet, and limit the sugar to a quarter-inch-thick layer, so it toasts evenly without requiring any stirring. The exact timing will vary depending on the accuracy of your oven. If it runs hot, youll have a hot mess in no time. If you dont have the assurance of a reliable oven thermometer, keep a close eye on the sugar your first time around, then adjust the temperature for future batches accordingly. Toast the sugar until it has a strong caramel aroma, but exhibits a rather subtle color change. Under a dingy oven light, you may not even notice the color shifting at all, so grab a spoonful of plain sugar for comparison. Stop before the sugar looks damp, a change that signals liquefaction is imminent—when youre dealing with small quantities of sugar in a metal skillet inside a 350°F oven, theres only a brief window of time between dry and wet, which will make the sugar lumpy and hard. With larger quantities, lower temperatures, and less conductive materials, like glass or ceramic, that window opens up considerably, allowing for the deeper degrees of caramelization shown in my original post on this sugar caramelization method.