Beat the egg whites and salt with the whisks of the hand mixer until stiff. Let 100 g sugar trickle in. Continue beating until the sugar has dissolved and a shiny mass has formed. Mix the cocoa and gingerbread spice, sieve over the beaten egg white and fold in.
Pour the beaten egg white into a piping bag with a perforated nozzle. Line a baking tray (32 x 39 cm) with baking paper. Spray egg white mixture in small tuffs on top. Bake in a preheated oven (electric cooker: 125 °C/ convection oven: 100 °C/ gas: not suitable) for approx. 45 minutes. Turn off the oven and let the tuffs cool down overnight.
Whisk butter and 2 tablespoons of sugar with a whisk of the hand mixer until white/creamy. Stir in crème fraiche by the spoonful. Fold in cardamom. Pour cream into a piping bag. Remove tuffs from baking paper. Spray some cream on the underside of a tuff. Place another meringue tuff with the underside on top. Repeat with the other meringue tuffs. Dust with cocoa powder to serve