Preheat oven to 350°. Combine first 4 ingredients. Beat eggs at medium speed with an electric mixer. Gradually add granulated sugar; beat until blended. Add chocolate and oil; beat until blended. Gradually add flour mixture; beat at low speed until blended. Fold in zucchini and pecans. Pour batter into a well-greased and floured bundt pan. Bake for 1 hour and 15 minutes, or until a wooden toothpick inserted in center comes out clean. Cool in pan 15 minutes. Remove from pan and cool completely on wire rack. Dust with powdered sugar before serving.