In a saucepan, over medium heat, add the blueberries, sugar, lemon juice, and ¼ cup water. Cook on low to medium heat until all the sugar has dissolved. Use a vegetable masher to mash some of the fruit. Pro tip - Mashing will add a nice thicker consistency to the topping but make sure to leave some blueberries whole.
Combine the remaining water with cornstarch. Add it to the blueberries. Continue to cook on low heat until the filling is thick and glossy. Pro tip - Cornstarch can settle to the bottom of the water so you must stir it just before adding it to the saucepan.
Remove and cool before you pour it over the cheesecake, or serve it alongside the cheesecake. Pro tip - The filling will thicken as it cools so keep that in mind when you take it off the heat.
Crush the graham cracker/biscuits in a food processor. Add sugar and the melted butter and stir to combine.Pro tip - You can also place them in a ziplock bag and use a rolling pin to crush them.
Pour crumbs into the prepared springform pan. Use the back of your spoon or measuring cup to press the crumbs firmly to form a crust.Pro tip - Pressing down firmly will ensure a good base for the cheesecake and it won't fall apart when you cut slices.
Bake in the oven for 10 minutes. Once baked set aside to cool slightly.
Reduce the oven temperature to 300°F / 150°C/ Gas Mark 2.
In the bowl of a stand mixer, with the whisk paddle attachment, combine cream cheese and sour cream. Then, add the sugar. Followed by the cornflour and vanilla extract.Pro tip - The cream cheese must be at room temperature. Otherwise, the batter will be lumpy. And if necessary, place a warm bowl on top of the cream cheese to help thaw faster.
Add the eggs, one at a time, making sure to incorporate each well.Pro tip - We want each egg to incorporate well but we do not want to incorporate too much air into the batter. Otherwise, the top will crack when baking. So, do not overmix.
Double boiler - Pour the batter into the prepared springform pan over the baked crust. Place the springform pan in a deep baking pan or roasting rack. Pour 2 cups of hot water into the roasting rack outside the springform pan. Pro tip - The water will create steam in the oven and prevent the custard-based cheesecake from drying out.
Bake for 70 to 80 minutes until set. Remove from the oven and let cool for 30 minutes on the counter. Then, run a knife or spatula around the edge of the cake but do not remove it from the pan. Pro tip - As the cheesecake cools it will shrink slightly. Running the knife around will prevent any cracks on the top of the cheesecake.
Chill and topping
Chill the cheesecake for at least 4 hours - preferably overnight. You can pour the blueberry filling over the cheesecake before chilling it. Or, serve the blueberry filling along with the cheesecake as I have done here.
Temperature - Always have your ingredients at room temperature. If necessary delay it by a few minutes just so they thaw. You can thaw cream cheese in the microwave at 50% power for 10 secs at a time. Do not melt it as it does alter the taste. Place eggs in warm water to thaw – room temperature eggs mix well in the cheese batter and works best for consistency.
Quality - Use good quality high-fat cream cheese, like mascarpone Philadelphia as they are thicker in consistency as compared to low-fat cream cheese, which can affect the consistency of your baked batter.
Pans - Prepare your baking pans properly. Use a springform pan when baking a cheesecake. When baking in a water bath foil the outside of the pan to prevent water from getting into the cheesecake.
Mixing - Never over-mix a cheesecake batter as this will incorporate air and lead to cracking.
Crust - bake the cheesecake crust for 10 to 12 minutes before you add the cheesecake crust. This will prevent a soggy crust later.
Baking - Since cream cheese batter is similar to a custard, baking in a water bath helps keep the custard batter soft and supple rather than dry and spongy. This also prevents cracking.
Cooling - Run a knife around the edges of the cheesecake before you cool it. This will prevent the cake from cracking as it shrinks while cooling. Make sure to let the cake cool properly. This also helps the custard set and you will be able to make pretty, neat slices. Of course, a chilled cheesecake is also more delicious than a warm one.
Make-ahead - it is always best to make the cheesecake a day ahead of serving. This cheesecake can be made up to 3 days ahead. It will keep well in the fridge for 5 days. Alternatively, you can freeze this cheesecake for up to 3 months.
Water bath - A water bath is simply placing the cake pan in a large roasting pan. Then pour hot water into the roasting pan (outside the cake pan). The steam created by the water helps the custard-based cheesecake bake without cracking. Alternatively, you can place another large baking pan with water on the bottom of the oven if you don't have a large roasting pan or are afraid that the springform pan may leak.
The nutrition information and metric conversion are calculated automatically. I cannot guarantee its accuracy. If this data is important to you please verify with your trusted nutrition calculator. Thank you