Preheat the oven to 170°C / 325°F / Gas Mark 3. Lightly grease a 23 x 28 cake tin and Line the bottom of the tin with greaseproof paper.
To make the cheesecake mixture:
Whisk 60g of the caster sugar with the cream cheese, the 1 tablespoon flour and the egg yolk together, then cover with cling film and set aside in the fridge to chill.
To make the brownie cake mixture:
If using, place the pecans on a baking tray and bake in the oven for a few minutes - then chop them roughly.
Mix the chopped nuts with the 200g flour and set aside.
Place the remaining sugar and the eggs in a large bowl and beat until thick and pale.
Place the broken chocolate in a pyrex bowl and melt it over hot water in saucepan on the stove. Do not let any water into the bowl.
Cut the butter into small pieces and add to the melted chocolate mixing well.
Fold the chocolate mixture into the beaten eggs and sugar, then fold in the flour and nuts.
Spoon or pour the chocolate mixture into the tin.
Using two teaspoons, drop little spoonfuls of the cheesecake mixture in rows. Tap them down so that they sink into the brownie cake part
Bake for at least 40 minutes. The brownies will look a little paler and a skewer will be reasonably clean, when stuck into the cake.
Remove them from the oven and allow to cool before slicing.