In Which I Attempt, and Fail, to Level Up at Baking

I am trying to learn the secrets of the jelly roll cake.  My first attempt, while not a complete loss, wasn't really a win either. I made a lemon cake with lemon custard.  While I was suspicious of the internet recipe for not including butter, the lemon cake part of the cake was good and fluffy and lemony.  But then I put in too much custard, so it oozed out when I rolled the cake up, I broke the cake a little rolling it up, oh, and I'm weak at custard, didn't spend long enough stirring, and it has a very sharp taste.

Nonetheless, dear friends, onward!  Once more into the breach!  What jelly roll cake shall I measure my skills against next?