Preheat electric oven to 350°F. Grease or spray a baking sheet. In a large bowl, beat eggs, sugar, and almond flavoring. Sift flour, cocoa, baking powder, and salt; add to sugar mixture. Using your hands, mix to form a stiff and sticky dough; add additional flour if necessary. Divide dough in half. Form dough into two logs, 12 x 2-inches and place on prepared baking sheet. Bake for 25 to 30 minutes. Remove from oven and cool for 5 minutes. Cut each log diagonally into 1/2-inch slices. For crisp biscotti, bake at 300°F for 20 to 25 more minutes. Combine powdered sugar and water; drizzle over biscotti. Make 20 biscotti. For mocha-flavored biscotti, add 2 tablespoons of coffee powder to the liquid ingredients.