How to keep thin sponge bases moist? I enjoy making multi layered sponge cakes (specifically chiffon sponge), but I find that when cooking a much thinner base than for a normal sponge (around 1cm height), I am faced with a decision of having an undercooked sponge or having one that is perfect in the middle but a bit crunchy around the edges.

Is there anything I can do to make sure that I get the same moistness in smaller bases as I do in larger ones?
Is there a reason you're not just baking a standard thickness and splitting it into layers?  This is going to give you more control.

If you have troubles moving the layers without breaking them, have a piece of cardboard handy (traditionally a cardboard cake round would be used by any would work) and after cutting the cake horizontally, lift up the edge of the top piece to slide the cardboard under and then proceed to push it all the way under the top layer before carefully removing the layer.  Proceed with the next layer.

If they cake is a bit dry but not crunchy, moisten the cut surface by brushing with simple syrup on its own if you don't want any added flavor, or add a bit of a complementary-flavored liqueur to the syrup before moistening.