Most low-carb desserts replace wheat flour with alternative flours - usually almond flour or coconut flour, or a combination of both. Almond flour is surprisingly easy to bake with. It produces fluffy baked goods with a tender crumb. My only issue with this flour is that baked goods made with it are usually high in calories. Coconut flour is not as easy to work with. It's extremely absorbent, so you need to add quite a few eggs and enough liquid to any mixture that contains it. However, once you get the ratios right, baked goods made with coconut flour are light and fluffy (these coconut flour muffins are a good example), and they are also very low in calories. Especially compared with almond flour baked goods which tend to be calorie-dense.