What do you call the action of making desserts?

Solution 1:

The cooking school, Le Cordon-Bleu USA, refers to the field as the pâtisserie and baking arts. It also uses the term pastry arts.

The Culinary Institute of America uses the same phrases.

Solution 2:

French here. The word you're looking for is pâtisserie making.

Actually, as long as all desserts are not pastries, the term "entremet making" would fit better than "pâtisserie making" here.

Solution 3:

This question is looking for a verb. The verb is confection:

https://en.wiktionary.org/wiki/confection#Related_terms

In noun form, a confection is an edible thing made with sugar. In order to create a confection, you would first need to confect it, similar to the way that "perfection" is possessed by that which has been "perfected."

Example: "Have you confected those lemon bars yet?" or: "Confection is easy. You just put your hand around the icing tube... and squeeeeeze." or: "Don't make so much noise when I'm confecting!