As a professional recipe developer focused on baking, I am more aware of the cost of eggs than most folks. Try making a custard tart that calls for eight egg yolks, then testing it three more times.

In addition to dialing back the fat, I swapped in arrowroot flour (also known as arrowroot starch) for some of the flour, which Joe Yonan uses in the vanilla cake from his new book “Mastering the Art ...