By Fiona Cairns
This all-in-one method takes no time at all to whip up, is completely fail-safe and gives a delicious buttery sponge.
You can choose to cook this cake either in 1 × 20cm sandwich tin or in 2 × 20cm sandwich tins. Butter the tin or tins, then line the bases with baking parchment. If you use just 1 tin, line the sides with a 7c