Crush the biscuits until they resemble fine crumbs.

Melt the butter and mix into the biscuit crumbs along with the sugar replacement and vanilla.

Press the mixture into a prepared round 9 inch springform cake pan (or into the bottom of a glass or pyrex dish.

Bake at 160C for about 5 minutes.

Allow to cool while assembling the filling.

Beat the ricotta, sour cream and sugar replacement until smooth.

Add the eggs one at a time and beat to incorporate.

Add the lemon juice and vanilla and mix well.

Once your base is cool, slowly pour the filling on top and smooth out the top.

Bake in a 160C oven for 50 minutes. The top will begin to turn brown and crack around 45 minutes. This is normal.

Run a knife around the edge of the cake and then allow the cake to cool to room temperature before transferring to the fridge for at least 2 hours.

Once the cake is chilled you can remove it from the pan.