Preheat oven to 350 degrees. In the bowl of an electric mixer, whisk together flour, granulated sugar, baking powder, ginger, salt, pistachios, and coconut. Add dried fruits after beating the dough for about two minutes. Transfer to mixer fitted with the paddle attachment. Add eggs; beat until a stiff dough comes together, about 3 minutes.
Divide dough in half. Form each half into a 12-inch log. (Dough may be sticky; dampen your hands for easier handling.) Transfer to a parchment-lined baking sheet and flatten so each log is 13 inches long, 2 1/4 inches wide, and 3/4 inch thick.
Brush logs with beaten egg and sprinkle with sanding sugar. Bake until firm and very pale golden, about 35 minutes. Let cool on pans on a wire rack, 40 minutes. Meanwhile, reduce oven temperature to 300 degrees.
Using a serrated knife with a sawing motion, cut logs into slices slightly thicker than 1/4 inch. Arrange, cut-side up, on parchment-lined baking sheets. Bake until dry to touch, about 30 minutes. Let cool completely on pans on racks, 30 minutes. Store in an airtight container up to 1 month.