Try doing a task while on the way to completing another one. Jill can only carry one cake at a time but she can hand out menus, collect money, tune the television, bake another cake and frost cakes all while holding a cake in her hand. For example try the following.

As a cake is done baking, start baking the next customer's order before the first cake is taken to be frosted.

Hand out menus to the new customers on the way to pick up cakes from the oven.