Chop the candied lemon peel very finely. Separate the eggs. Beat the fat, 75 g sugar and 1 pinch of salt until thick and creamy. Gradually add the egg yolks and fold in the candied lemon peel.
Whip the egg whites with 25 g sugar until stiff, fold in the poppy seeds. Fill into a cake springform pan (22 cm ø) with parchment paper. Bake in a hot oven at 180 °C (gas 2-3, convection oven 160 °C) on the 2nd rack from the bottom.
Bake for 30 minutes.
Cook the vanilla sauce with the milk. Dust the tart with powdered sugar while it is still warm.