Biscotti cookies are intended to be hard! That’s what is so fabulous about them. The intention is to dip them into a warm drink, and they will hold up and not become a soggy mess. So, if your gluten-free biscotti turn out hard, then you did exactly what you were supposed to do! Note: if your biscotti are too soft, then it likely means that you didn't bake them long enough the second time you put them into the oven! Also keep in mind that these cookies will firm up further when they cool.