Line baking form (30 x 20 cm) with baking paper.
Wash rhubarb and cut in about 1 cm pieces.
Mix rhubarb, sugar, vanilla and optional raspberries in a pot and bring to boil, cover with a lid.
When liquid builds up, remove the lid and leave to boil until the rhubarb is soft. Remove and leave to cool.
For the Brownies; melt chocolate and butter over bain-marie.
Mix flour, cocoa powder and salt in a bowl.
Whisk eggs and sugar in a separate bowl until light and creamy.
Mix in chocolate-butter-mix.
Fold in flour-mix.
Cream Cheese; Briefly stir the cream cheese.
Add sugar and egg in cream cheese and stir briefly.
Spread brownie batter (put 4 tbsp apart for later) into the baking pan.
Place cheesecake mixture in blobs on top of brownie batter.
Place rhubarb (without the liquid) in blobs on top.
Place rest of brownie batter on top.
Pull a wooden stick through the batter and swirl (for the marble effect).
Bake in preheated oven at 170°C for about 35 minutes.
Leave to cool and cut in pieces.
The raspberries only give the color in the rhubarb mixture, so not essential.