1. Place pecans in a single layer in a shallow pan.
2. Bake at 350° for 8 to 10 minutes or until toasted, stirring once after 4 minutes.
3. Beat sugar and butter at medium speed with an electric mixer until blended. Add eggs, 1 at a time, beating until blended after each addition.
4. Whisk together mashed sweet potatoes, orange juice, and vanilla extract. Combine flour and next 5 ingredients. Add flour mixture to sugar mixture alternately with sweet potato mixture, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Fold in toasted pecans. Place foil baking cups in muffin pans, and coat with vegetable cooking spray; spoon batter into cups, filling two-thirds full.
5. Bake at 350° for 28 to 30 minutes or until a wooden pick inserted into center comes out clean. Remove immediately from pans, and cool 50 minutes to 1 hour or until completely cool. Spread cupcakes evenly with Cream Cheese Frosting. Garnish, if desired.