Canned sweet potatoes and packaged graham cracker crumbs are great time-savers. For the smoothest, most velvety texture, purée the potatoes completely so there are no lumps.
Preheat oven to 350°.
To prepare crust, combine first 4 ingredients, tossing with a fork until well blended. Press into bottom of a 9-inch springform pan coated with cooking spray. Bake at 350° for 10 minutes; cool on a wire rack. Reduce oven temperature to 325°.
To prepare filling, place yogurt and cheeses in a large bowl; beat with a mixer at high speed until smooth. Lightly spoon flour into a dry measuring cup; level with a knife. Add flour and next 7 ingredients (flour through nutmeg); beat well. Add eggs, 1 at a time, beating well after each addition.
Place sweet potatoes in a food processor; process until smooth. Add sweet potatoes to cheese mixture, stirring until well blended.
Pour cheese mixture into prepared pan. Bake at 325° for 1 hour and 20 minutes or until cheesecake center barely moves when pan is touched. Turn oven off. Cool cheesecake in closed oven 1 hour.
Remove cheesecake from oven; run a knife around outside edge. Cool to room temperature. Cover and chill at least 8 hours.