Preheat oven to 325°. Stir together first 4 ingredients in a bowl until well blended. Press mixture on bottom and 1 1/2 inches up sides of a 9-inch springform pan. Bake 8 to 10 minutes or until lightly browned.
Beat cream cheese and next 2 ingredients at medium speed with a heavy-duty electric stand mixer until blended and smooth. Add eggs, 1 at a time, beating just until blended after each addition. Add sweet potatoes and lemon juice, beating until blended. Pour batter into prepared crust. (Pan will be very full.)
Bake at 325° for 1 hour or until almost set. Turn oven off. Let cheesecake stand in oven, with door closed, 15 minutes. Remove cheesecake from oven, and gently run a knife around outer edge of cheesecake to loosen from sides of pan. (Do not remove sides of pan.) Cool completely on a wire rack (about 1 hour). Cover and chill 8 to 24 hours.
Remove sides and bottom of pan, and transfer cheesecake to a serving plate. Prepare Praline Topping; immediately pour slowly over top of cheesecake, spreading to within 1/4 inch of edge. Garnish, if desired.