FOR THE CRUST
11/2 cups graham cracker crumbs (from about 12 whole graham crackers)
1/4 cup sugar
1/3 cup unsalted butter, melted

FOR THE CHEESECAKE FILLING
1 (8-ounce) package cream cheese, softened
1 cup sugar
1/4 cup packed light brown sugar
1 3/4 cups mashed sweet potatoes (see note)
2 large eggs, slightly beaten
2/3 cup evaporated milk
2 tablespoons cornstarch
1/4 teaspoon ground cinnamon
1/8 teaspoon freshly ground nutmeg

FOR THE TOPPING
2 cups sour cream, room temperature (1 16-ounce container)
1/3 cup sugar
1 teaspoon vanilla extract

  1. Heat oven to 350 degrees. In a medium bowl, mix graham cracker crumbs, sugar and butter-until combined. Press evenly onto bottom and 1 inch up the side of a 9-inch springform pan. Bake until set but not brown, 6 to 8 minutes. Remove from oven, and cool.
  2. Beat cream cheese with electric mixer until smooth. Add sugar and brown sugar, beating until completely smooth. Scrape down the sides of the bowl. Add sweet potatoes, eggs, evaporated milk, cornstarch, cinnamon and nutmeg, beating until well combined. Pour into crust. Bake until edge is set, 45 to 55 minutes.
  3. Whisk sour cream, sugar and vanilla to combine. Spread over warm cheesecake. Return to oven and bake until just set, 5 minutes. Cool completely on wire rack. Remove side of pan, and chill at least 5 hours, and preferably overnight.

NOTE For 1 1/2 cups mashed sweet potatoes, you’ll need to roast 1 pound sweet potatoes (about 2 medium sweet potatoes). Using a fork, pierce the potatoes in several places and roast in a 400-degree oven until tender, 45 minutes to 1 hour. Once the sweet potatoes are cool enough to handle, cut them in half, scoop out the flesh and mash until smooth.