Well, a biscotti that's all fruit and nuts with a thin covering of batter. Depends what specifically you miss about them. The crunch?

Biscotti are twice-baked, right? That link at the bottom used twice-baking to make crackers, but you could try it with biscotti-thickness slices to make them crispy.

Or you could try using more batter in proportion to the fruit & nuts. I'm not making any promises about non-concrete though!