Crust
2 cups vanilla wafer crumbs
6 tablespoons butter, melted
1/4 cup granulated sugar

Combine, and press onto the bottom and 1 1/2 inches up the sides of a greased 10-inch springform pan. Bake at 350 degrees F for 10 minutes; cool completely.

Filling
32 ounces cream cheese, softened
1 cup granulated sugar
4 eggs
1 cup (8 ounces) sour cream
10 (1 ounce) squares white baking chocolate, melted

In a mixing bowl, beat cream cheese, sugar, eggs and sour cream just until blended. Add chocolate. Pour into crust. Bake at 350 degrees F for 1 to 1 1/4 hours or until center is nearly set. Cool to room temperature, about 2 hours.

Topping
1 cup (8 ounce) sour cream
3 tablespoons granulated sugar
1/2 to 1 teaspoon orange extract
2 (11 ounce) cans mandarin oranges, well drained

Combine sour cream, sugar and orange extract. Spread over filling. Bake at 450 degrees F for 5 to 7 minutes or until set. Chill, uncovered, for 1 hour.

Arrange oranges on cheesecake. Cover and chill at least 4 hours.

Yields 12 to 16 servings.