Roll out the puff pastry 20 cm wide (about 1/2 cm thick) and place on a baking sheet sprinkled with water. Bake at medium heat for about 25 minutes. Then cut in half while still hot and let cool.
Dissolve gelatin in water according to package directions.
Whip the cream until stiff. Add the sugar and add the dissolved gelatine while beating continuously. Finally, add the cherry brandy and the cherries.
Place one of the puff pastry sheets on a serving plate and spread thickly with the cherry mixture. Cover with the second plate.
For the glaze, mix all the ingredients for about 10 minutes and then immediately brush over the top half of the pastry.
Cut the finished glazed cake plate with a knife (dipped in hot water) into slices about 4-5 cm thick and serve.