Heat oven to 350°F. Coat 13 x 9 x 2-inch baking pan with nonstick cooking spray. Line bottom and sides of the pan with foil, leaving 2 inches overhang on the short sides.
In a large bowl, stir together the brownie mix and almonds (if brownie mix contains packet of chocolate syrup, save the syrup for another use, such as drizzling over ice cream or slices of pound cake garnished with berries). Stir the eggs, water and almond extract into the brownie mix until the ingredients are moistened and a stiff batter forms. With a spatula, spread the batter in the prepared pan in an even layer.
Bake in 350°F oven 35 minutes or until the cake is firm to the touch in the center. Using the foil overhang, carefully remove the brownie from pan to a wire rack. Let the brownie cool for 5 minutes.
Cut brownie in half lengthwise, scoring the surface with a serrated knife and completing the cutting through with a large, sharp knife. Then cut crosswise, into 3/4-inch-thick slices. Place brownies, cut side down, on large baking sheet .
Bake in 350°F oven 23 to 25 minutes, until biscotti are crisp. Transfer biscotti to wire rack; let cool.