Prepare Crust: Preheat oven to 425°. Sprinkle surface with 2 Tbsp. powdered sugar. Roll piecrust into an 11-inch circle on prepared surface. Fit piecrust, sugar side down, in a 9-inch pie plate; fold edges under, and crimp. Prick bottom and sides with a fork. Bake at 425° for 10 minutes or until golden. Cool completely on a wire rack.
Prepare Creamy Lemon Filling: Beat cream cheese and sour cream at medium speed with an electric mixer until smooth. Add 1/2 cup granulated sugar and next 2 ingredients; beat until smooth and fluffy. Spoon Creamy Lemon Filling into prepared crust; cover with plastic wrap, and chill until ready to serve (up to 24 hours).
Prepare Strawberry Topping: Process 1 1/2 cups chopped strawberries in a blender or food processor until smooth, and press through a wire-mesh strainer into a 3-qt. saucepan, using back of a spoon to squeeze out juice; discard pulp. Stir 1 cup granulated sugar into juice in pan.
Whisk together cornstarch and 1/4 cup water; gradually whisk cornstarch mixture into strawberry mixture. Bring to a boil over medium heat, and cook, whisking constantly, 1 minute. Remove from heat, and whisk in butter. Cool 15 minutes.
Toss together strawberry mixture and 10 cups hulled strawberries gently in a large bowl until coated. (Halve some berries; leave others whole.) Cover; chill 3 hours or until cold.
Prepare Vanilla Cream: Beat heavy cream and vanilla at medium-high speed until foamy; gradually add powdered sugar, beating until soft peaks form.
Spoon Strawberry Topping onto pie; top with Vanilla Cream. Serve immediately.