If you wish to freeze these, coat with chocolate after thawing to room temperature.
Position a rack in the center of the oven. Preheat the oven to 350┬░F. Grease a cookie sheet.
Spread in separate small baking pans:
1 1/3 cups whole blanched almonds
1 1/3 cups whole hazelnuts
Toast, stirring occasionally, until the almonds are tinged with brown and fragrant, and the hazelnut skins are loosened, 8 to 12 minutes. Let cool, then rub the hazelnuts in a dish towel or between your palms to remove as much skin as possible. Coarsely chop the nuts.
Chop into small bits:
6 ounces bittersweet chocolate or semisweet chocolate
Whisk together thoroughly:
3 cups all-purpose flour
1/4 cup unsweetened cocoa
2 1/2 teaspoons baking powder
1/4 teaspoon salt
Beat on medium speed until very fluffy and well blended:
8 tablespoons unsalted butter, softened
1 cup sugar
Beat in 1 at a time:
3 large eggs
1 large egg white
Add and beat until the coffee is dissolved:
1 1/2 tablespoons light corn syrup
1 tablespoon instant coffee granules or coffee powder
1 1/4 teaspoons vanilla
1 1/4 teaspoons almond extract (optional)
Gradually stir the flour mixture into the egg mixture until well blended and smooth. Stir in the nuts and chocolate.
Shape the dough into 2 smooth, evenly shaped 15 x 1 1/2-inch logs, arrange on the sheet, and flatten either by wrapping each log in plastic and rolling it back and forth until smooth, or by shaping it with lightly floured hands. Bake for 35 minutes. Remove the sheet to a rack. When the logs are just cool enough to handle, carefully transfer to a cutting board and cut crosswise, on a slight diagonal, into 1/2-inch-thick slices. Lay the slices flat on the sheet. Return to the oven and bake until the slices are almost firm when lightly pressed on top, 16 to 20 minutes. Transfer the biscotti to racks to cool.
To prepare for adding the optional drizzled chocolate, arrange the slices in neat rows about 1/2 inch apart on the cookie sheet. Melt, stirring often, in the top of a double boiler over barely simmering water:
4 ounces bittersweet chocolate or semisweet chocolate, coarsely chopped
1 tablespoon corn oil or canola oil
Remove the top of the double boiler from the bottom and add, off the heat:
2 ounces bittersweet chocolate or semisweet chocolate, cut into 1/2-ounce pieces
Stir until the melted chocolate cools to just barely warm. Remove any unmelted chocolate. Immediately spoon the chocolate into a paper cone or a pastry bag fitted with a large writing tip. If using a paper cone, cut off the tip to allow a 1/8-inch-wide drizzled line. Quickly drizzle long zigzag lines back and forth until all the biscotti are decorated. Let stand, chocolate side up, in a cool room until the chocolate is completely set, about 30 minutes.
