Add the flour, corn starch, vanilla extract, and salt and beat on medium for about 2 minutes. Then, add the eggs and beat on low until smooth. Again, scrape the sides of the bowl and add the remaining eggs. Beat on medium for 3 minutes.
Add the lemon juice and beat on low for about 1 minute, or until well combined. Again, scrape down the sides of the bowl and beat again.
Pour the cheesecake mixture into the cake tin. Make sure the mixture is even.
Sprinkle the cup of blueberries on top of the cheesecake. Because the blueberries contain a lot of water they should hopefully sink to different depths. If not, press the blueberries in further.
Place into the oven and bake for 1 hour.
Reduce the oven temperature to 110˚C and bake for 1 hour.
Reduce the oven temperature again to 95˚C and bake for 1 ½ hours or until the cheesecake starts to turn a very faint light brown. Do not open the oven door for about 30 minutes, as this will slow down the cooking process.
Remove from the oven and leave to cool.
Place into the fridge for 12 hours.
Prepare the icing.
Beat the sour cream, vanilla liqueur, and caster sugar for 2 minutes.
Release the cheesecake from the sides of the spring-form cake tin, be careful not to rip the crust away from the cheesecake. If, however this does happen, heat the crust in the microwave on high for 30 seconds and press the crust back onto the cheesecake. You will need to put back into the fridge for about 2-3 hours, if the crust does come away.
Spread the sour cream topping onto the cake with a rubber spatula, spread evenly across the top.
Arrange the blueberries in any pattern. I suggest starting in the centre and creating multiple circles. Place into the fridge for 30 minutes before serving.