We attempted the Espresso Cake over the weekend (fairly novice bakers) and followed the recipe very closely.
At 20mins the cake was not done (oven running a little lower than 190degrees according to the thermometer) so we left it in for a little longer.
On tasting - it was a little dry. Is this likely to be simply "over-cooking" or should we consider other trouble shooting tips?
Your cake being a little dry is most likely because it was baked for a little too long. If you bake beyond the suggested time because it doesn't seem ready, keep a close watch and check every few minutes to make sure it's not getting over baked.
Hope that helps and happy baking!