Preheat oven to 350.Wash sweet potatoes and place on a foil or parchment lined baking sheet.Bake for 1-1½ hours, until potatoes are very tender.Remove from oven and allow to cool just enough to be able to peel.Put peeled sweet potatoes in bowl of large mixer.Mash potatoes with fork or potato masher.Turn on mixer and beat potatoes on low.Add butter and mix until completely absorbed. If your potatoes got too cool then you can melt the butter first.Add salt, nutmeg, cinnamon, ginger, and sugars, and mix well.Add eggs, vanilla, and orange juice and mix well.Add cream and mix well.Spoon into buttered dish.Sprinkle topping over sweet potatoes.Bake at 375 for 30-45 minutes.In a large mixing bowl, stir together flour, brown sugar, cinnamon, and salt until well mixed.Using your fingers, work the butter in until the mixture resembles large crumbs.Stir in the pecans and mix well.Do not over mix or your topping will turn mushy.Sprinkle all of the topping evenly over the sweet potatoes prior to baking.