Soak the gelatin in a little cold water. Peel the apple is cut into thin slices and place in a small saucepan on the stove to soften for two three minutes, then add chopped pieces of pineapple with juice. Bring to a boil and pull the fire. Blend well. Drain gelatin and add in more warm puree and blend again. Allow the mixture to cool in the meantime, beat the cream of very hard snow and add to already tepid puree. Melt two tablespoons of sugar in three tablespoons of water and add the liqueur to your liking. Halve biscuits into two parts and immerse them in the syrup for a short lay them only board tray (20 cm) littered with plastic foil. In the center pour the mousse and smooth to even surface. Leave in the fridge for at least six hours. Before serving, clean, wash and dry the strawberries. Cut them into pieces and blend them well by adding two tablespoons of lemon juice and two powdered sugar. Filter through a strainer to remove the seeds. Put in a suitable deep dish in which you can fit and mousse. Carefully remove the mousse from the tray and place it on a strawberry sauce.