Have ready an ungreased 10-inch tube pan or angel food pan, or two 9 inches round ungreased cake pans. If you’re using two round pans, place a rack in the center of the oven; for a tube pan or angel food pan, place a rack just below the center, so the top of the risen cake won’t be too close to the top of the oven.
In a large mixing bowl, beat the egg whites with the cream of tartar or lemon juice until foamy. Gradually add 1/2 cup of the sugar and continue beating until stiﬀ and glossy. Set aside.
Whisk together the remaining 1 cup sugar with the flour, baking powder, and salt and set aside.
In a separate bowl, beat the oil, milk, egg yolks, and flavorings until pale yellow.
Add dry ingredients and beat until well blended, about 2 minutes at medium speed using a stand mixer, or longer with a hand mixer.
Gently fold in the whipped egg whites, using a wire whip or cake blender. Be sure to scrape the bottom of the bowl so the batter is well blended. Pour batter into your pan(s).
If you're using a tube or angel food pan, bake the cake for 50 minutes, then turn up the heat to 350 degrees F for 10 minutes more or until a toothpick inserted into the cake comes out clean. If you're using two 9-inch round cake pans, bake for 40 minutes at 325 degrees F, then 10 minutes more at 350 degrees F or until a toothpick comes out clean.
Cool the cake upside-down in the pan for 30 minutes before using a thin, sharp knife between the cake and the pan to remove it. If you've used a tube pan, set it atop a thin-necked bottle, threading the bottle neck through the hole in the tube. (Cooling with the cake on the bottom and the pan on the top helps keep the sponge light and airy._
Meringue Buttercream Frosting
Combine the egg whites, powdered sugar, and salt in the bowl of a large stand mixer fitted with a paddle attachment. Mix on low speed, until the sugar is moistened and no dry patches remain. Turn off the mixer, scrape down the sides and bottom of the bowl with a spatula, then turn the mixer to medium speed. Beat on medium for minutes.
After 5 minutes, turn the mixer to medium-low and start adding the room temperature butter, 1 to 2 tablespoons at a time. Once all the butter is incorporated, add the vanilla extract and mix until incorporated. Stop the mixer and scrape down the bottom and sides once more. Turn the mixer on to medium speed and beat the buttercream for 10 minutes. The frosting should be light and fluffy in texture.
To assemble: Place the completely cool cake onto a platter or pedestal. Frost the top of cake with Meringue Buttercream Frosting. (If you have made two cakes, you could fill the layers with more buttercream or with jam or curd.) Adorn with elements of the outdoors for decorations, if you like.
Marmee's Birthday Cake Recipe from JaMonkey https://jamonkey.com/a-collection-of-little-women-recipes/