1. Pre Heat your oven to 150 C. Grease a 27 x 18cm baking tin, as well as line with grease proof paper. The paper must cover both the base and come up the sides with enough extra bits sticking out for you to use to lift your entire cooked cheesecake out of the tin when it is cooked and cooled. Very important! If you dont line with paper with enough edges left out, you will struggle to get it out of the tin. I have made this mistake before and it was a complete mess!
2. For the base, beat the sugar and butter together in a large bowl until light and fluffy. Add the flour, salt and semolina/cornflour and bring everything together to form a dough; try not to overwork it.
3. Press the mixture onto the base of your tin, making sure to press it in evenly. Prick the base all over with a fork. Bake for 35mins until cooked but still pale. Do not over bake so keep an eye on it. Once baked, leave to cool in tin.
4. Turn your oven up to 175C and begin making your filling.
5. In a large bowl with an electric mixer, or using a stand mixer mix 100g of your cream cheese with the custard powder and beat until smooth. Now add 1 Tbsp of your sugar, and another 100g cream cheese and beat until smooth. Add the rest of your sugar and cream cheese in bit by bit to ensure that you get a smooth blend. Make sure to scrape down the sides and base of the bowl to ensure everything is nicely mixed in. Take time to do this stop properly to ensure a velvety smooth cheesecake!
6. Now add the eggs one by one, and then your cream and vanilla.
7. Carefully fold in your fresh or thawed blueberries.
8. Spread the 100g of Blueberry Jam over your biscuit base, and then over that pour your creamcheese mix.
9. Place your baking tin in a larger baking tray or roasting pan and pour enough cold water in the larger roasting pan so that the water comes halfway up the sides of your cheesecake baking tin. This is called bain marie style baking which gently cooks the cheesecake rather than having direct heat onto the cheesecake mix whilst baking. Bake for 35mins – and if using a fan over, turn the fan off so that it bakes consistently and not too quickly. Keep an eye on it and check at 30mins – you want it to be just set – it must not have any colour on the top but set and have just a gentle wobble.
10. Lift out of the water bath baking tin and allow to cool on a wire rack before transferring into a fridge. Refrigerate for at least 4 hrs before serving, even better overnight.
11. Remove from fridge, slip a smooth knife around the sides of the tin to loosen the paper and using the paper edges carefully lift your entire cake out of your tin and onto a board. Using a sharp knife cut into neat slices (warm the knife in a little warm water to help keep the slicing neat!).