Preheat oven to 350°F. Line 2 baking sheets with parchment sheets.
Combine cake mix, flour, butter, eggs and vanilla extract in a large bowl. Beat at low speed with mixer until well blended. Mix in cranberries, nuts and lemon rind.
Divide dough in half. Shape each half into a 22 x 2-inch log, place logs on prepared baking sheets. Bake logs separately.
Bake 30 to 35 minutes or until wooden pick inserted in center comes out clean. Remove from oven and cool on baking sheets 15 minutes.
Using a serrated knife, cut each log into 1/2-inch slices on a diagonal. Arrange slices on baking sheets. Bake slices 10 minutes. Remove to cooling racks and cool completely.
Dip one end of cooled biscotti in melted chocolate. Allow chocolate to set at room temperature before storing biscotti in an airtight container.Servings: 44 slices