Preheat oven to 180 C / Gas 4. Grease a rectangular or square baking tin and line with aluminium foil so that there is a 3cm overhang all around. Grease foil.
In a small saucepan melt butter and chocolate over low heat whilst stirring.
In a bowl stir flour and salt.
Pour chocolate mixture in a bowl and add sugar, vanilla and flour. Stir in eggs one after the other, beating the an electric mixer till the sugar is fully incorporated.
Evenly spread 2/3 of the mixture in the tin.
Stir cream cheese with sugar, vanilla sugar, melted butter, egg and zest till creamy. Scatter tablespoon size globs of the mixtures over the brownie base.
Scatter teaspoons of the raspberry jam on top and move a large knife in spirals through the mitre to create a marble effect.
Bake in the preheated oven for 42 minutes. The bottom layer should still be slightly moist (insert a toothpick to test).
Place the tin on wire rack to cool, then gently lift the brownies out of the tin with the foil. Cover loosely with foil and chill in the fridge for a couple of hours before cutting into squares or rectangles.