Set the oven to 175 degrees and lubricate a mold with removable edge, 24 cm in diameter.
Melt the butter in a saucepan and remove from the heat.
Stir together eggs and powdered sugar in a bowl. Add cocoa, flour, vanilla sugar and salt. Stir in the melted butter and stir together to form a batter.
Pour half of the batter into the mold. Press down on the cookies and spread the rest of the jam cake over. Bake in the middle of the oven for 20-25 minutes. Let the cake cool for about 2 hours in the refrigerator.
Make oreo fudge. Melt the dark chocolate in a bowl over the water bath and mix down half of the condensed milk.
Melt the white chocolate and mix down the remaining condensed milk.
Chop the cookies, put a little aside for garnish. Then stir down half of the chop into the dark chocolate and half into the white chocolate mixture.
Swirl the two chocolate creams over the cake and pull a fork through to form nice “swirls”. Top with remaining cakes and then set in the refrigerator for 30 minutes.