Disclosure: I make a small commission from your Amazon purchase through my website at no added cost to you.
Vegan desserts can be just as yummy, and better for your health, than non-vegan desserts. Note I said can be. Foods high if fat and/or sugar are best used in moderation.
If not required for consistency, a recipe's sugar can often be cut in half. Personally I like desserts sweetened with stevia. But even with stevia you can get too much of a good thing. Not that it's bad for you, but too much tastes strange or bitter, and most recipes using stevia I have tries call for way too much. If you can sample the recipe as you go, add stevia slowly, to taste.
Fat can sometimes be replaced with applesauce and other fruit purees in baked goods, without compromising texture or flavor. Many low-fat recipes will have that already built in, or you can substitute it yourself. See this Bon Appetite article for some specifics on that.
Here are some vegan dessert cookbooks for you to consider, available at Amazon.
Voilà Vegan: 85 Decadent, Secretly Plant-Based Desserts from an American Pâtisserie in Paris: A Baking Book
Sweet Vegan Treats: 90 Recipes for Cookies, Brownies, Cakes, and Tarts
Chloe's Vegan Desserts: More than 100 Exciting New Recipes for Cookies and Pies, Tarts and Cobblers, Cupcakes and Cakes--and More!
Incredible Plant-Based Desserts: Colorful Vegan Cakes, Cookies, Tarts, and other Epic Delights
Vegan Chocolate: Unapologetically Luscious and Decadent Dairy-Free Desserts
The Beginner's Guide to Gluten-Free Vegan Baking: 60 Easy Plant-Based Desserts for Any Occasion
