Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9-inch round cake pan.
In a small bowl, stir together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla. Beat in the flour mixture alternately with the sour cream. Fold in the chopped fresh strawberries. Spread evenly into the prepared pan.
Bake in the preheated oven for 35 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool in pan for 10 minutes, then turn out onto a wire rack and cool completely.
Place the cake on a serving plate. Spread the strawberry jam over the top of the cake. In a medium bowl, cream together the butter, cream cheese, confectioners' sugar and vanilla until smooth. Fold in the chopped fresh strawberries. Spread over the top of the cake.