Q: If I’m satisfying two Guests on my turn, can both of them be served the same Dessert card, as long as each icon is only used once?

A: No. Each Guest must be served their own separate Desserts. You can’t, for example, serve a Spice Cake to one customer to satisfy their Cake craving, and somehow pull the Spices out of it to add to donuts to make a Cinnamon Roll for someone else.

By the same token, limitations on one Guest will not affect what you may serve the other Guest.