In a saucepan, melt 2 ounces chocolate and butter over low heat, stirring constantly; spread or brush over the bottom and up the sides of pastry shell. Chill.
Meanwhile, in a mixing bowl, beat cream cheese, sour cream, sugar and vanilla until smooth. Spread over chocolate layer; cover and chill for 2 hours. Arrange strawberries, tip end up, atop the filling. Brush jam over strawberries. Melt the remaining chocolate and drizzle over all.