1. Heat oven to 350, or 325 for non-stick or dark colored pans. Prepare a bundt pan or 10 x 4 angel food cake tube pan with cooking spray and flour.
2. Beat cake mix, pudding mix, sour cream, butter, 1/4 c rum, orange peel, and eggs on low speed 30 seconds, then beat at medium speed 2 minutes. Fold in pecans.
3. Spread in pan and bake 40-45 minutes (or 48-52 minutes for dark or nonstick pans) or until a toothpick comes out clean. Cool 15 minutes, then remove from pan and allow to cool completely.
4. Sprinkle with 2 T powdered sugar, if desired.
5. Store loosely covered.