Brownies are a gluten free bakers best friend and a great place to start out. They use less flour than regular cakes, so the missing gluten has less of an effect on your results. There also intentionally dense meaning that even if you under or over-bake, you’ll get away with it. I always use use chocolate with a hight coco content in my gluten free brownies, which helps your brownies set properly once out of the oven. And I add a little xanthan gum to mix just to be safe.
