Preheat the oven to 170 ° C. Roast the poppy seeds on a baking sheet in the hot oven until it begins to smell. Let cool and grind.
Now stir the marzipan and the egg until smooth. Place in a bowl with the egg yolks, blossom honey and vanilla pulp. Beat in a water bath to form a light yellow foam (sabayon), which must have a maximum temperature of 80 ° C. Take the bowl out of the water bath and keep beating until the sabayon is cold again. Whip the cream until semi-firm and fold it into the sabayon with the poppy seeds.
Lightly oil a box or terrine dish (1.2 l capacity) and line it with cling film. Pour in the parfait mass and leave to freeze in the freezer for at least 5 hours until you are ready to eat it.