For the batter, beat the sugar and eggs until frothy. Sift in the flour and carefully fold together. Spread the batter on a lined baking sheet and smooth. Bake for about 10 minutes.
For the topping, soften the gelatin in cold water. Drill the coconut, drain the milk, crack open the shell and remove the pulp. Cut 1/4 of the coconut pulp into fine slices. Lightly saute the coconut slices.
Coarsely mash the remaining coconut pulp. Beat the cream until stiff. Mix the mashed coconut, quark, coconut liqueur, sugar and gelatin with a little hot water over low heat. Gradually stir in the cream. Spread the pineapple jam on the cooled cake. Spread the cream on the cake and smooth. Cover with the coconut slices. Chill and serve.