Preheat oven to 350 degrees F.
Grease Bundt pan generously with shortening; be sure to grease the inner and outer circles.
Mix together pecans, sugar and cinnamon.
Sprinkle 1/3 of the cinnamon mixture into the greased pan; be sure to get the cinnamon mixture to coat all surfaces of the pan.
Mix together cake mix, pudding mix, eggs, sour cream, orange juice, vegetable oil and vanilla; add green food coloring for a darker color of green if desired.
Add half of the cake batter to the pan and top with half of the remaining nut mixture.
Top with the remaining cake batter and add the remaining nut mixture.
Use a knife to create swirls in the cake. Be sure to go around the entire cake.
Bake for 45 to 50 minutes or until toothpick comes out clean.
Cool for 5 minutes before inverting onto a cake platter.
For glaze: Mix together orange juice, vanilla and powdered sugar. Pour over cooled cake.