DIRECTIONS:

1. Preheat the oven to 160C. Line the base of the cake tin with parchment paper. For the crust, melt the butter in a medium pan. Stir in the biscuit crumbs and sugar so the mixture is evenly moistened. Press the mixture into the bottom of the pan and bake for 10 minutes. Cool on a wire rack while preparing the filling.
2. Increase the oven temperature to 200C. In a table top mixer fitted with the paddle attachment, beat the soft cheese at medium-low speed until creamy. With the mixer on low, gradually add the sugar, then the flour and a pinch of salt, scraping down the sides of the bowl and the paddle twice.
3. Continue by adding the vanilla, lemon zest and juice. Whisk in the eggs, one at a time, scraping the bowl and whisk at least twice. Stir the sour cream or yogurt. Whisk to blend, but don’t over-beat. The batter should be smooth, light and somewhat airy.
4. Pour the filling into the tray – the top should be as smooth as possible. Bake for 10 minutes. Reduce oven temperature to 90C and bake for 25 minutes more. If you gently shake the tin, the filling should have a slight wobble. Turn off the oven and open the oven door for a cheesecake that’s creamy in the centre, or leave it closed if you prefer a drier texture. Let cool in the oven for 1-2 hours. The cheesecake may get a slight crack on top as it cools.
5. Combine 50ml sour cream with the icing sugar for the topping. Spread over the cheesecake right to the edges. Cover loosely with foil and refrigerate until cooled.
6. Run a round-bladed knife around the sides of the tin to loosen any stuck edges. Unlock the side, slide the cheesecake off the bottom of the tin onto a plate, then slide the parchment paper out from underneath.