Preheat oven to 300=B0F. Grease and flour baking sheet. Using an electric mixer with a dough hook attachment, combine flour, 1 C. sugar, baking soda and powder, and salt in a large bowl until blended. In a small bowl, whisk 2 eggs, 1 egg yolk, vanilla, and orange zest. Add egg mix to flour mix; continue beating until a soft dough forms. Turn onto a lightly floured surface. Add walnuts and knead 3 minutes or until walnuts are evenly distributed. Divide dough in half. On baking sheet, shape each piece of dough into a 2.5 x 25 cm loaf, flouring hands as necessary. Allow 8 cm between loaves on a baking sheet. In a small bowl, combine remaining 2 T. sugar and cinnamon. In another small bowl, beat remaining egg and water. Brush loaves with egg mixture; sprinkle with sugar and cinnamon mix. Bake 45 to 50 minutes or until loaves are lightly browned. Cool 10 minutes on baking sheet. Cut loaves diagonally into 1 cm slices. Lay cut cookies flat on a baking sheet. Bake 15 minutes, turn cookies over, and bake 15 minutes longer. Transfer cookies to wire rack to cool completely. Store in an airtight container. Makes about 2.5 dozen biscotti. Recipe By : Nancy Dooley ----