Fluffy Chocolate Sponge Cake

Gather all the necessary ingredients for the recipe.

Measure each one, dividing the sugar into two smaller bowls of 150g each. 

Combine the flour with the baking powder.

Pour boiling water into the cocoa and blend well using a fork or spoon to remove any lumps.

Separate the egg whites and yolks into two large bowls.

Whisk the egg whites. Once they start to stiffen, gradually incorporate 150g of sugar. The result should be a firm meringue-like texture.

Beat the yolks with the remaining 150g of sugar. Gradually add the oil until fully combined.

Next, integrate the slightly cooled cocoa mixture.

Lastly, add the flour and baking powder mixture. Mix thoroughly using a whisk or mixer to eliminate any lumps.

Fold this mixture gently into the beaten egg whites in 2-3 stages, using upward motions to avoid deflating the whites.

Pour the batter into a round pan (28 cm in diameter) lined with baking paper or greased with butter and dusted with flour. 

Gently tap the pan 2-3 times to level the dough and release air bubbles.

Bake in a preheated oven at 180°C (356°F) for approximately 40 minutes, or until it passes the toothpick test. The toothpick should come out clean.

Allow the cake to cool slightly before removing it from the pan, then let it cool completely.

If the top is domed, trim it carefully with a thin knife for a flat and even surface before decorating.

Here's a cut view, ready for final assembly.

This is how it looks with the bottom facing up - it's the perfect smooth surface for decorating. Enjoy your cake!