Place cream cheese and sugar in a medium bowl and beat with an electric mixer until well combined. Add the sour cream, lemon juice and vanilla and beat until the mixture is smooth and well combined. Spoon and spread filling into the piecrust. Freeze the pie until the filling is set, about three hours. Cover and keep frozen until needed.
When ready to serve, warm the pie at room temperature a few minutes, and then cut into wedges and plate. Top wedges of the pie with fruit, dust with icing sugar, and serve.
Note: Ready-to-use graham cracker piecrusts are sold in the baking supply aisle.