Melt semisweet chips in the microwave or double boiler, set aside.
Mix together sugar, oil, eggs, vanilla, and jam.
Sift together flour, cocoa, baking powder, and salt, and gradually add to sugar mixture.
Stir in melted chocolate, then white chocolate chips.
Batter will be thick! Pour into baking pan, spreading to cover.
Bake 25-30 minutes or until a toothpick inserted in the center comes out dry. Let cool for as long as you can possibly stand it before cutting. Eat a few and then take to your friends before the whole pan is gone.