An easy recipe for making sponge cake requires chefs to whisk eggs and sugar together, add warm milk and butter to the eggs, and add flour, salt and baking soda to the egg and milk mixture. Bake the cake at 350 degrees Fahrenheit for 15 minutes.
Preheat the oven to 350 degrees Fahrenheit, and warm 1/2 cup of milk in a saucepan with 2 teaspoons of unsalted butter. After the milk is warm, turn the heat off. In a mixing bowl, whip 8 large eggs and 1 cup of sugar until the mixture triples in volume using a hand mixer with the whisk attachment. Turn the mixer to low, and incorporate the milk mixture into the egg mixture.
Place 1 cup of all-purpose flour, 1/8 teaspoon of salt and 1 teaspoon of baking powder into a bowl. Sift the dry ingredients. Add half the dry ingredients to the egg mixture. Mix well, and add the second half of the dry ingredients to the mixture. After mixing the batter to incorporate the dry ingredients, add 1 teaspoon of vanilla extract, and mix the batter again. Pour the batter into a 17-by-12-inch baking dish that is greased with 2 tablespoons of unsalted butter, and sprinkle 2 tablespoons of sugar on top of the batter. Bake for about 15 minutes at 350 degrees Fahrenheit.