Grease a tart mould with a removable base (26 cm Ø) and dust with flour. Roll out the shortcrust pastry on some flour (approx. 30 cm Ø). Line the tart mould with the pastry, pressing it on the edge.
Prick the base of the dough several times with a fork. Chill briefly.
Roughly grate the marzipan. Cream butter and sugar. Stir in marzipan, liqueur and eggs. Mix flour and baking powder and stir in briefly. Spread on the tart base. Bake in a preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see
manufacturer) on the lowest rack for about 20 minutes.
Wash, clean and pat dry the gooseberries. Spread on the tart. Bake the tart for about 25 minutes. Let it cool down.
Mix icing sugar and 1 tablespoon of water to make a glaze. Pour into a freezer bag and cut off a small corner at the bottom. Decorate the tart with icing strips and let it dry.