1. Preheat the oven to 150C. Triple wrap a 23cm round springform pan with foil. Grease the sides of the tin with butter.

Base:

1. Add the butter (50g) to the bowl. Program 4 minutes / 50C / Speed 2, or until melted.
2. Add the biscuits (100g) to the bowl. Mill Speed 10 / 10 seconds.
3. Transfer the biscuit mixture to the tin and gently press it down into the base, corners and slightly up the sides.
4. Clean and dry the bowl.
5. Boil a kettle full of water.

Filling:

1. If you need to make your own caster sugar, add sugar (150g) and grind Speed 9 / 3 seconds. Set aside.
2. In the clean, dry mixer bowl, place the mascarpone (500g). Mix Speed 4 / 20 seconds.
3. Add the ricotta cheese (1kg), eggs (5), caster sugar (150g), lemon zest (from 1 lemon), lemon juice (from 1 lemon) and vanilla (1/2 tsp) to the bowl. Program 1 minute / Speed 5, using your spatula to help process the mixture through the lid.
4. Pour the filling onto the biscuit crust and even out with a spatula.
5. Put the springform pan inside a large roasting pan and transfer to the oven.
6. Fill the roasting pan with boiling water, up to about 4cm up the side of the springform pan. This will create steam and allow the cake to bake evenly. Bake in the oven for 1 hour 15-25 minutes. It should be lightly browned and still wobble in the middle.
7. Once baked, turn off the oven and leave the cake inside for 1 hour.
8. After that, remove from the oven and place on a wire cooling rack to cool down completely.
9. Once cool, remove from the tin and place in the fridge for at least 4 hours before eating. Enjoy!