Wash and peel the apples. Cut them into small cubes, reserving 3 pieces for decoration. Drizzle the apple cubes with lemon juice.
Put the yogurt in a bowl. Whip the sweet cream until stiff peaks form, about 2 minutes. Add about 4 tablespoons of the whipped cream to the yogurt, sprinkle a pinch of cinnamon powder over it, and mix well.
Divide the apple cubes among 3 serving glasses. Top each with the cinnamon yogurt cream and garnish with one reserved piece of apple and one amarettini biscuit.