Chocolate and Vanilla Chip Biscotti

Oven to 350F. Spray 1 large or 2 small cookie sheets with nonstick cooking spray. In medium bowl, combine flour, cocoa and baking powder; mix well. In large bowl, combine sugar, brown sugar and margarine; beat until well blended. Add eggs; beat well. Add flour mixture; mix well. Stir in vanilla chops. With sprayed hands, shape dough into three 7" rolls. Place rolls 3" apart on cookie sheet; flatten each to 7x3" rectangle. Bake for 22 to 28 min. or until set and light golden brown. Remove from cookie sheet; place on wire racks. Cool 5 min. With serrated knife, cut rectangles into 1/2" slices. Arrange slices, cut side up, on ungreased cookie sheet. Bake for 6 to 8 min. or until top surface is slightly dry. Turn cookies over; bake an additional 6 to 8 min. or until top surface is slightly dry. Remove from cookie sheet; cool 15 min. or until completely cooled. Store in tightly covered container. Yield 4 doz.