1. Line the base of a 20-cm/8-inch spring-form round dish with parchment paper and lightly grease the sides.
2. Crush the cookies for the base and add to a mixing bowl with the melted butter, and stir well to a consistency that resembles wet sand. Pour into the tin and press down firmly to make a compact base and sides of the cheesecake case. Transfer to the fridge while you continue.
3. For the cheesecake filling, add all of the ingredients to the bowl of a freestanding mixer and beat for 3-5 minutes until really light and fluffy (if the filling is not whipped enough, the cheesecake will be runnier).
4. Pour the cheesecake into the case and smooth over the top.
5. Chill in the fridge overnight (you can cover with clingfilm, if you like) until set firm to touch. If needed, place in the freezer for 1 hour to firm up.
6. Carefully remove from the tin and place on a serving plate. Decorate with extra whipped cream, some cookies, redcurrants, and a dusting of cinnamon.
7. Store leftovers in a sealed container in the fridge for 1 week or in the freezer for 1 month. If the slices are too soft, pop them in the freezer for 1 hour and then thaw a little before eating.