These are delicious. I buy the ginger in a large bag from Hoosier Hill Farm on Amazon. It is sliced and I cut it into bits about the size of small currants.
The basic dough recipe is adapted from Martha Stewart's Fruitcake Biscotti, as are all my biscotti recipes (Dark Cherry-Walnut, Dried Apricot-Almond, etc.)
INGREDIENTS
4 cups all-purpose flour (spooned and leveled)
1 1/2 cups granulated sugar
1/4 cup cornmeal
1 tablespoon baking powder
1/2 teaspoon fine salt
1-1/2 teaspoon ground ginger
3/4 teaspoon ground cinnamon
1/2 teaspoon ground cardamon
1 teaspoon dried lemon peel
2 sticks cold unsalted butter, cut into bits
4 large eggs plus 1 beaten large egg white, divided
1 1/2 cups chopped candied ginger
1 1/2 cups chopped walnuts
Ginger sugar or sparkling sugar for sprinkling
DIRECTIONS
Preheat oven to 325 degrees, with racks in upper and lower thirds. In the bowl of a stand mixer, using paddle attachment, combine flour, granulated sugar, cornmeal, baking powder, salt, and spices.
Add butter and beat on medium-high until coarse crumbs form. This will take 5 minutes or more.
With mixer on low, add eggs, one at a time, beating after each addition. Mix in ginger and walnuts.
On parchment-lined baking sheets, shape dough into four 3-inch-wide logs. Brush with egg white; sprinkle with sanding sugar. Bake until just set in middle, 30 minutes. Let cool completely on sheets on wire racks. With a serrated knife, cut logs on the diagonal into 1/4-inch slices. Bake on parchment-lined baking sheets until just golden, 15 to 20 minutes, rotating sheets halfway through. Let cool on sheets on racks.
