Take the butter and eggs out of the fridge about 2 hours earlier to warm up.

Grease the baking pan with butter and sprinkle with flour or breadcrumbs - you can also line it with baking paper.

Turn on the oven to heat to 160 degrees (convection mode).

Grate the marzipan on a coarse grater.

Sift the flour together with the baking powder.

Mix together butter, sugar, vanilla, and lemon zest - I mix them together on high speed for about 5 minutes.

Add grated marzipan and mix on high speed.

Add one egg at a time to the butter mixture and mix briefly after each addition - just until combined.

Add ground almonds to the batter and mix briefly.

Pour in the lemon juice and mix briefly.

Add the flour with baking powder in portions, mixing briefly on low speed - stop mixing when you can still see traces of flour.

Briefly mix the batter with a spoon and transfer it to the prepared pan.

Bake the cake in the preheated oven for about an hour - until a skewer comes out clean.

Completely cool the cake after baking before pouring the glaze.

Sift the powdered sugar into a bowl and add lemon juice in portions - mix thoroughly until you get a slightly liquid but thick glaze.

Glaze the top of the cake with the icing.