It is normal for the dough to be quite sticky. The easiest way to handle the dough is to either dust hands and dough with a little extra flour and work quickly. Do not add extra flour to the dough or you may end up with tough or flavorless biscotti. Alternatively, try wetting your hands before handling the dough (do not sprinkle dough with flour if you go this route). It may seem counterintuitive to wet your hands when the dough is so wet, but it actually helps to keep the dough from sticking to your fingers while you shape it.