Cream fat, sugar, vanillin sugar and salt. Stir in eggs bit by bit. Mix flour, almonds, cornstarch and baking powder and stir briefly into the fat mass. Grease a wreath mould (26 cm Ø, 21/2 litre capacity) or a springform pan with a tube bottom insert (26 cm Ø) and sprinkle with breadcrumbs.
Pour in the dough and bake in the preheated oven (electric: 175 °C/ gas: level 2) for approx. 50 minutes. Let the finished wreath rest in the mould for approx. 10 minutes. Then turn out of the tin and let it cool down on a cake rack.
In the meantime, stir the pudding powder with 3 tablespoons of sugar and 7-8 tablespoons of milk until smooth. Bring the remaining milk and lemon zest to the boil. Add the pudding powder while stirring and bring to the boil again briefly. Finally stir in lemon juice.
Put the pudding in a bowl, cover with foil and let it cool down. Roast the flaked almonds in a dry pan. Cut the almond wreath twice. Spread the lower and middle base with jelly.
Whip butter and remaining sugar until creamy white. Stir the lemon pudding well and stir into the butter by the spoonful. Pour some of the butter cream onto the leaved bases and assemble the wreath.
Spread with butter cream all around and press on the flaked almonds. Put the rest of the buttercream in a piping bag with a star nozzle and spray circles on the wreath. Chill for 1-2 hours. Warm up the remaining jelly and spread into the circles.
Keep cool until serving. Decorate with lemon balm leaves.