Cut the mango off the stone. Peel the flesh and cut into small cubes. Cream eggs, 225 g sugar and vanillin sugar. Stir in flour, baking powder, oil and mango lassi. Fold in half of the mango cubes.
Grease a box form (2 litres capacity; 30 cm length) and dust with flour. Add the dough and smooth it down. Bake in the preheated oven (electric range: 175 ° C/ convection oven: 150 °C/ gas: level 2) for 50-60 minutes.
Remove the cake and let it cool in the mould for 10 minutes. Then turn out onto a cake rack and let it cool down for about 3 hours. Put the mango slices and juice into a high mixing bowl and puree. Bring mango puree, lemon juice and 1 tablespoon of sugar to the boil.
Stir the starch and 4 tablespoons of water until smooth, stir into the mango puree and bring to the boil again. Stir the remaining mango cubes into the mango sauce. Spread the mango compote over the cake.