line 8 inch square cake pan with foil, leaving overhang for handles. Set aside. in heatproof bowl over saucepan of hot water, melt chocolate; let cool slightly. meanwhile, in seperate bowl, beat cream cheese with half Splenda until smooth. Beat in 1 egg and half the vanilla; set aside. in seperate bowl, beat butter with remaining Splenda, until fluffy. Beat in remaining egg. Beat in all but 2 tbsp of the jam and the remaining vanilla and then the chocolate, mixing well. In small bowl, whisk together flour, baking soda and salt, mix into chocolate batter just until combined. Spread chocolate batter in prepared pan. Spread with cream cheese mixture. Spread remaining jam in small droplets over top. With knife, zigzag through cream cheese and jam layers for marble effect. Bake in 350 until tester in centre has only a few crumbs clinging, about 40 minutes. Let cool in pan or rack. Cover and refrigerate until chilled, about 2 hours. Remove from pan. Cut into squares, wiping knife between slices.