Step 1: Preheat the Oven

Preheat your oven to 180°C (350°F) and grease two 20cm (8-inch) round cake tins. Line the base of the tins with parchment paper.

Step 2: Whisk the Eggs and Sugar

In a large mixing bowl, crack the eggs and add the caster sugar. Using an electric whisk or stand mixer, beat the eggs and sugar together for about 5-7 minutes, or until the mixture becomes pale, thick, and triples in volume. It should leave a ribbon-like trail when the whisk is lifted.

Step 3: Fold in the Flour

Sift the self-raising flour over the egg mixture in small batches. Gently fold the flour into the egg mixture using a spatula, being careful not to knock out too much air. Add the vanilla extract at this stage if using. Avoid overmixing, as this could deflate the batter.

Step 4: Divide and Bake

Carefully divide the batter between the two prepared cake tins, smoothing the tops with a spatula. Bake in the preheated oven for 20-25 minutes, or until the sponges are golden and spring back when gently pressed in the center.

Step 5: Cool the Cakes

Once baked, remove the cakes from the oven and leave them to cool in their tins for 5 minutes. Then, turn them out onto a wire rack to cool completely.

Step 6: Assemble (Optional)

Once the cakes have cooled, you can fill them with your favorite filling, such as whipped cream and jam. Sandwich the two sponges together and dust the top with icing sugar before serving.