Drain the cherries and let them drain well. Mix pudding powder with 8 tablespoons of milk and sugar. Bring the remaining milk and poppy seeds to the boil, remove from the heat and stir in the custard powder. Bring to the boil again briefly while stirring. Stir in mascarpone. Pour some cream on the bottom of an ovenproof dish.
Spread three lasagne plates on top. Spread 1/3 of the remaining poppy seed cream on top. Sprinkle half of the cherries on top and again cover with 3 lasagne sheets. Spread 1/3 of the cream and the remaining cherries on top. Cover with the rest of the lasagne and finish with the remaining cream. Bake in a preheated oven (electric: 175 °C/ gas: level 2) for 45 minutes