Butterscotch Orange Cheesecake

1 1/4 cups old fashioned oats, uncooked
1/4 cup margarine, melted
1/4 cup packed brown sugar
2 tablespoons flour
24 ounces cream cheese, softened
3/4 cup granulated sugar
2 teaspoons grated orange peel
1 teaspoon vanilla extract
4 large eggs
1/2 cup packed brown sugar
1/3 cup light corn syrup
1/4 cup margarine, melted
1 teaspoon vanilla extract

Heat oven to 350 degrees F.

Combine oats, margarine, brown sugar, and flour; press onto bottom of 9-inch springform pan. Bake for 15 minutes. Reduce oven temperature to 325 degrees F.

Combine cream cheese, granulated sugar, orange peel and 1 teaspoon vanilla extract, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition; pour over crust. Bake at 325 degrees F for 1 hour and 5 minutes.

Loosen cake from rim of pan. Chill.

Combine brown sugar, corn syrup and margarine in saucepan; bring to boil, stirring constantly. Remove from heat; stir in 1 teaspoon vanilla extract. Chill until slightly thickened. Spoon over cheesecake. Garnish with orange slice and fresh mint, if desired.