Sweet Potato Cheesecake with Pecan Praline Sauce

For the crust:
1-1/2 cups finely ground ginger cookie crumbs
3/4 cup toasted pecans, ground
6 tablespoons unsalted butter, melted

For the filling:
8 ounces cream cheese or Mascarpone cheese, softened
1/2 cup sugar
1/2 cup dark brown sugar
1 teaspoon ground cinnamon
3/4 teaspoon ground ginger
1/4 teaspoon ground cloves
1/2 teaspoon ground nutmeg
1 cup puréed sweet potato (or yam; the orange kind, not the yellow kind)
5 eggs
1/2 cup heavy cream

For the praline sauce:
8 ounces unsalted butter
1 cup dark brown sugar, packed
1 cup heavy cream
1/2 cup chopped toasted pecans

In a large mixing bowl, mix the ground pecans and cookie crumbs; add the melted butter and mix well. To form the crust, press the crumb mixture into the bottom of a 9-inch springform pan. Refrigerate for at least 30 minutes.

In a mixer, beat the cream or Mascarpone cheese until smooth, then add the sugars and spices and beat until the mixture is light and fluffy, approximately 3-4 minutes. Add the sweet potato purée and mix until just blended. Add the eggs one at a time, scraping bowl after each egg. Stir in heavy cream at low speed until completely blended.

Pour the filling into into the pan. Put the pan into a 1 to 1/2 inch bain marie, or warm water bath (it's a good idea to wrap the bottom and sides of the springform pan to prevent water from leaking in.) Cook the cheesecake in the bain marie for 50 minutes at 350°F.

Cool the cheesecake at room temperature for 45 minutes. Chill for at least 4 hours before serving.

While the cheesecake is cooling, make the praline sauce: melt the butter in a saucepan, then add the brown sugar, cream and pecans. Bring to a boil over high heat, then reduce the heat and simmer for 5 minutes. Keep warm.

To serve, place each serving a slice of pie onto a dessert plate, then spoon a pool of warm praline sauce over and around each serving. Top with a dollop of fresh whipped cream, and garnish with a sprig of mint.