Prepare pastry for single crust pie. Line a 9-inch pie plate as directed. Cover the pastry with a double thickness of foil. Bake in a preheated 450-degree oven for 8 minutes; remove foil and bake for 5 more minutes or until golden brown. Let cool.
In a medium saucepan, combine 1/2 up of the brown sugar and 1/4 cup of the butter. Cook and stir over low heat until butter melts and mixture is smooth. Remove from heat.
In a small bowl, combine the remaining brown sugar, the flour and cornstarch. Add flour mixture to butter mixture; stir until combined. Gradually stir in whipping cream. Return saucepan to heat. Cook and stir over medium heat until thickened and bubbly; reduce heat. Cook and stir for 2 minutes more. Remove from heat.
In a small bowl, lightly beat egg yolks with a fork. Gradually stir about 1 cup of the hot filling into yolks. Add yolk mixture to saucepan. Bring to a gentle boil over medium heat, stirring constantly; reduce heat. Cook and stir for 2 minutes more. Remove from heat. Stir in 3 Tbsp. butter and the vanilla. Pour filling into the baked pastry. Cover filling with plastic wrap. Chill for at least 2 hours before serving.
Whipped Cream Topping: Beat 1-3/4 cups whipping cream until soft peaks form. Add 1/4 cup powdered sugar and 1/4 teaspoon vanilla. Beat until stiff peaks form.
Remove plastic wrap from pie. Spread topping evenly over cold filling. Immediately serve pie or store, covered, in the refrigerator.