Melt the butter. Grind Amarettini, up to 16 pieces for decoration, and butter biscuits finely in a universal chopper. Mix the breadcrumbs and butter, press them into an oiled springform pan (24 x 24 cm) as a base and rim. Chill for about 30 minutes.
Wash the potatoes thoroughly, cut or slice them thinly. Place them in a gratin dish like roof tiles. Wash and chop the rosemary and sprinkle over the potatoes with a little sea salt. Sprinkle with 4 tablespoons of oil. Bake in a hot oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer) for about 40 minutes.
Wash mint, shake dry and pluck leaves from the stalks. Chop leaves, up to 16 for decorating. Mix cream cheese, 1 sachet of cream firming agent, icing sugar and chopped mint. Whip the cream until stiff, while pouring in 1 sachet of cream firming agent and fold into the cream cheese cream. Pour the cream onto the compote and spread. Approx. 30 minutes
Carefully remove the cake from the ring and cut it into pieces. Moisten mint leaves and sprinkle with 1 tablespoon of sugar. Decorate pieces with sugared mint leaves and amarettini. Sprinkle with caramel sauce if desired.