Melt butter in a pot. Remove from the heat and let it cool down a little. Fill the biscuits into a large freezer bag and crumble them finely with a rolling pin. Mix cookie crumbs and butter well. Spread the round tart tin with lift-off base (26 cm Ø) with oil. Put the crumbs into the tart tin, press them down firmly to a smooth base with a rim. Put the base in a cool place for about 30 minutes.
Roast the almonds in a pan without fat until golden brown, take them out. Stir sour cream, eggs, custard powder, sugar and advocaat until smooth. Spread the cherries on the base and pour the icing over the cherries. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 30 minutes. Remove the tart from the oven, let it cool down for about 15 minutes, lift the base out of the mould. Let the tart cool down on a cake rack. Sprinkle almonds on the tart and arrange on a plate
Waiting time approx. 15 minutes