In a large pot, bring 2 gallons water to a boil over medium-high heat. Add peeled sweet potatoes to the pot and cook 45–60 minutes or until tender. Strain, mash and set aside. Preheat oven to 400°F. In a medium bowl, combine 1 cup flour, ½ cup softened butter, ¼ cup sugar, ½ tsp cinnamon and egg yolk until mixture forms into a ball. Pat ¾ of dough onto the bottom of 10-inch springform pan with the sides removed. The bottom crust should be ? inch thick. Bake 8–10 minutes or until crust begins to brown on edges. Reduce oven temperature to 300°F. Attach the sides to the springform pan and pat remaining dough 1 inch from the top of pan. Set aside. In a medium bowl, beat sweet potatoes, craisins, 1 tablespoon melted butter, 1 teaspoon cinnamon, nutmeg and vanilla with electric hand-mixer on low speed until blended. Set aside. In a large bowl, beat cream cheese and 1 cup sugar on medium speed until smooth. Beat in sweet potato mixture on low speed until well blended. Beat in eggs, one at a time, until incorporated. Spoon batter into crust. Place springform pan into a larger, deep pan, carefully filling the deep pan with hot water up to half height of the springform pan. Bake cheesecake about 1½ hours or until the center of the cheesecake is set, adding hot water to the deep pan as needed. To make the topping, in a small bowl combine all ingredients for topping. Set aside. Once cheesecake is done, sprinkle topping evenly onto the cheesecake. Bake 20 minutes or until topping is set. Remove cheesecake from pan of water. Cool cheesecake 30 minutes, loosen the sides from the pan then remove. Refrigerate uncovered, 3–4 hours or until chilled. When ready to serve, cut cheesecake into 8 equal slices and serve.