Preheat oven to 350 degrees F and grease a 9x9 inch Pyrex baking dish.
In a large bowl, cream the cream cheese, butter, and sugar with an electric mixer. Beat in egg, milk, and vanilla until smooth. Slowly mix in flour, baking powder, soda, and salt.
Spread batter evenly into baking dish.
Dollop jam on top and then swirl through batter with a knife.
Bake for 25-30 minutes or until toothpick comes out clean.