Place the Amaretti biscuits into a shallow dish and pour over the espresso. Leave to soak, turning once or twice.
Meanwhile, make the cream filling by whisking the mascarpone, cream, Amaretto, and sweetener (to your personal taste, I used 2 teaspoons) until thick and creamy. Do not over whip! Fold in most of the flaked almonds, reserving some for topping.
To assemble the Tiramisu, you will need two large wine glasses - or similar - small glass bowls would work well.
Place 4 Amaretti biscuits into each glass and add about half of the cream filling. Then grate over some dark chocolate and sprinkle over a little cocoa powder.
Layer the final 5 Amaretti biscuits into each glass, then add the remaining cream mixture.
Sprinkle over a generous dusting of cocoa powder, sprinkle with some more grated dark chocolate, and the remaining almonds.
Can be served immediately, but best served chilled.