Sponge cake layers are the basis for making a wide variety of confectionery products, from cakes to rolls.
However, if some inaccuracies are made during the preparation process, the biscuit will most likely settle after baking.
To prevent this from happening, first of all, make sure that the bowl you use to beat the eggs is clean and dry.
The same rule applies to the whisk and baking pan.
Please note: since over time microcracks form on plastic utensils, which become clogged with grease and other dirt, it makes sense to choose only glass or metal containers for making biscuits.
Another important point concerns the tool you use to mix the beaten eggs with the other ingredients.
It should never be a spoon, as this will cause the air to come out of the dough and the cake to sink.
And vice versa: a silicone or wooden spatula will come in handy.
