Grease a springform pan (26 cm Ø) and dust with flour. Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Mix 100 g flour and baking powder. Coarsely crush 150 g Amarettini with the ball of your hand.
Cream 100 g butter, eggs and sugar with the whisks of the mixer. Briefly stir in the flour mixture until a smooth dough is formed. Fold in crumbled amarettini and flaked almonds.
Put the dough into the mould. Add the frozen blueberries. Bake in a hot oven for about 50 minutes. About 10 minutes before the end of the baking time, sprinkle the remaining Amarettini on top. Serve with vanilla ice cream.