Nick and I have been friends for 50 years. (How this can be, I'm not sure, as neither of us is over 40.) And so I've been watching him cook and bake for decades, learning things almost by osmosis. This past Easter, I arrived early enough to watch him assemble and embellish this Cassata alla Siciliana. And then, later, to eat it. One of several terrific desserts he made for this baking-heavy holiday.