Why did my Victoria sponge cake crack on the top?

1. Oven temperature: If the oven temperature is too high, the cake will rise too quickly and crack. Make sure to preheat the oven to the correct temperature and check it with an oven thermometer to ensure it's accurate.

2. Over-beating the batter: Over-beating the batter can incorporate too much air, which can cause the cake to rise too quickly and crack. Be sure to follow the recipe instructions carefully and mix the batter only until the ingredients are combined.

3. Not enough liquid: If there is not enough liquid in the batter, the cake will be too dry and more likely to crack. Make sure to follow the recipe instructions carefully and add the correct amount of liquid.

4. Opening the oven door during baking: Opening the oven door during baking can cause the cake to fall and crack. Avoid opening the oven door until the cake is almost done baking and the sides of the cake no longer look wet.

5. Cooling the cake too quickly: Allowing the cake to cool too quickly can cause it to sink and crack. Let the cake cool slowly in the tin for at least 10 minutes before turning it out onto a wire rack to cool completely.