Crust
1 cup minced pecans, toasted
3/4 cup graham cracker crumbs
1/4 cup dark brown sugar
1/4 cup unsalted butter, melted

Preheat oven to 325 degrees F. Grease a 9-inch springform pan.

In a small bowl, mix together pecans, graham crackers crumbs and brown sugar. Pour in the butter, and stir to combine. Press the warm mixture into the prepared pan, packing it evenly around the bottom. Bake until the crust is set, about 10 minutes. Allow the crust to cool. It can be made a day ahead, if you wish. Raise the oven temperature to 350 degrees F.

Filling
1 pound cream cheese (at room temperature)
3 eggs
1/4 cup granulated sugar
1 1/4 cups chopped pralines
2 teaspoons minced orange zest
1/2 cup sour cream

Using a mixer, beat the cream cheese in a large bowl until it is light and fluffy. Add the eggs and then the sugar, continuing to beat until everything is well incorporated. Mix in the chopped pralines and the orange zest. Pour the filling into the prepared crust, and bake for 55 to 60 minutes, until the center is just firm.

Remove cheesecake from the oven, and let it sit for 10 minutes. Raise the oven temperature to 425 degrees F. Spread the sour cream gently and evenly over the top of the cheesecake. Bake an additional 5 minutes, until the sour cream bubbles at the edges. Cool the cheesecake completely on a rack.

Run a knife between the cake and the sides of the pan to loosen it. Cover the cake, and refrigerate it until it is well chilled, at least 3 to 4 hours (the cake can be made a day ahead of serving). Make the Caramel Sauce.

Caramel Sauce
2 teaspoons unsalted butter
1/2 cup dark brown sugar
2 tablespoons water
1/2 to 3/4 cup milk, warmed
1/2 teaspoon vanilla extract

Melt the butter in a heavy saucepan. Add the brown sugar and water, and cook over medium heat until the mixture reaches the soft-ball stage, 234 degrees F to 240 degrees F. Remove the pan from the heat, and let the mixture cool a couple minutes. Stir in the amount of milk necessary to achieve the sauce consistency you prefer. The sauce can be kept warm over a hot water bath or made ahead and re-warmed at serving time.

Serve the cheesecake topped with warm Caramel Sauce.