Preheat your oven to 190C/170C fan and line a 9x9inch square tin with parchment paper, and leave to the side for now.
Whisk/mix the plain flour, bicarbonate, salt and cornflour together so its evenly distributed – leave to the side.
In a larger bowl, melt the butter. Add in the two sugars, and whisk for about 2 minutes so the sugar starts to dissolve and the mixture is smooth. Add in the egg and the vanilla, and whisk again briefly until smooth. (I used an electric whisk)
Add in the dry ingredients and the chocolate chips and mix with a spatula until a thick cookie dough is formed.
Press all but a handful of the mixture into the bottom of the tin and press down.
In a bowl, beat the cream cheese until loose, and add the sugar and beat again until combined. Gradually beat in the egg until combined along with the vanilla.
Pour the cheesecake mixture on top of the cookie bars, and then sprinkle over bits of the spare cookie dough. Bake in the oven for 30 minutes! Once baked, leave to cool in the tin completely, and then refrigerate.
I used Callebaut chocolate chips for my chocolate as I adore the chocolate, but you could use any really. You could even use a chocolate bar which you have chopped into pieces. I also used Philadelphia cream cheese, but 250g of a full fat type would be ideal.
These delicious beings will last in an airtight container in the fridge for up to 3 days, but they’ll be eaten before then.
Sometimes they can still look a little underdone, but often baked cheesecake can do so. It will still have a ever so slight wobble, and when you touch it it will spring back, but it shouldn’t be liquid by any means.