Sponge cake texture is dry, light and resembled sea sponge. Sponge cake is used to make Swiss roll, Christmas log (Yule log) etc. I will bake some of these cakes.

About cakes

There are two basic cake types:
1 those made with fats
2. those containing little or no fats
Butter cakes, also called creamed cakes, contain butter, margarine or vegetable shortening, which contribute to a finely textured, tender and moist cake.
Cakes that do not contain fat, such as a sponge cakes, angel food or chiffon cakes, are often referred to as foam cakes. These cakes have a larger proportion of egg than butter cakes.
Sponge cakes
Foam cakes, such as sponge, angel food and chiffon cakes, rely on eggs for volume. Depending on the recipe, the whole egg, or only the yolk or only the white is whipped to incorporate air and  produce a light, fluffy batter and cake. The flavour of the cake will be affected by whether the egg yolk or egg white is used, and what other flavourings are added.

Preheat oven to 350 F (175 C) Butter and flour a 9-inch springform cake pan. or use what you have.

Ingredients
5 eggs
3/4 cup granulated sugar (I used 1/2 cup)
1 cup all-purpose flour
1/2 tsp. baking powder
3 tbsp. butter or margarine, melted
1 tsp. vanilla extract or flavouring

Method
step1
Place a stainless-steel bowl over a saucepan or pot filled with simmering hot water. Add the eggs and sugar, use a whisk to beat the eggs and sugar for 5 minutes.

After 5 minutes, turn off the heat and remove the bowl containing the eggs and sugar mixture from the pot with the hot water. Continue beating until the mixture slightly cools. Set aside.

step2
In a medium-size bowl, sift the flour and baking powder. Fold in the egg mixture using a spatula or whisk.

step3
Gently fold in the melted butter and vanilla using a spatula or whisk. Pour the batter into the cake pan

step4
Bake  in oven for 25-30 minutes. Remove from oven. Detach the cake from the pan by running a small knife around the sides. Let it for 5 minutes in the cake pan before turning out the cake onto a wire rack or cookie sheet or platter or a flat plate. Sprinkle with small amount of granulated sugar (optional) and allow to cool. (I did not sprinkle my cake with sugar;however, some people do

Sponge cake variations

Lemon sponge cake

• Replace vanilla with 1 tsp. grated lemon or lime peel.
• 1 tbsp.. lemon or lime juice
• 2 drops yellow food colouring

Orange sponge cake

• Replace vanilla with with 2 tsp. grated orange peel
• 1/2 tsp. orange blossom or 1 tbsp. orange juice
• 2 drops orange food colouring

Coffee sponge cake

• To butter, add 2 tbsp. instant coffee

Chocolate fudge sponge cake

• Melt 4 oz. semisweet chocolate. Let cool.
• Fold in after melted butter

Nut sponge cake

• Add 3/4 cup chopped nuts of your favourite choice (almonds, hazelnuts, pecans, pistachios, etc.) before melted butter

Chocolate chip sponge cake

• Into flour, fold 1/2 cup grated semisweet chocolate

Cocoa sponge cake

• Ina bowl, mix flour with 3 tbsp. cocoa.
• Fold in 2 tsp. vegetable oil
• 2 drops red food colouring, at the same time as melted butter

Sesame seed sponge cake

• Into flour, fold in 1/2 cup tasted sesame seeds

Poppy seed sponge cake

• Into flour, fold 1/2 cup poppy seeds

Spice sponge cake

• Into flour, fold 2 tsp. mixed ground spices (cinnamon, clove, nutmeg, etc.)

Tomato sponge cake

• Add 1/2 cup tomato paste at the same time as butter

Mixed herb sponge cake

• Add your choice of 1/4 cup mixed herbs (basil, thyme, etc.) before melted butter