Almond biscottis are twice-baked biscuits originating in the Italian city of Prato. The biscuits are oblong-shaped almond nibbles, made dry and crunchy through cutting the loaf of dough while still hot and fresh from baking in the oven. After starting a scan of New Lantea, Dr. Rodney McKay was going to the Atlantis mess hall to get some almond biscottis and a Yoo-hoo. (SGA: "Remnants")
The original, literal meaning of the French 'bis-cuit', and the German 'zwei-backen', is 'twice-baked'. Technically, in Italian 'biscotti' is already a plural, from 'biscotto' (same meaning), and so there really shouldn't be an -s added.