Chocolate cheddar cheesecake

I've made a couple of cheddar cheesecakes using this original recipe, and had modified it to orange-flavoured one before. Thinking it would be quite straight forward to make it into a chocolate version, but it resulted to something quite different. At first glance, it looks like the Magic Custard Cake, which I've bookmarked but yet to try. Without making comparison to the original cheddar cheesecake and to eat this cake on its own merit, I would say it's pretty good. 

Chocolate cheddar cheesecake

(makes a 8" x 8" square pan) 

Ingredients:
6 slices of Cheddar Cheese
100ml fresh milk
100g unsalted butter
6 egg yolks
6 egg whites (preferably cold, place in fridge after separating)
100g caster sugar
75g cake flour
25g cocoa powder 

Method: 

1. In a heatproof saucepan, place the butter, fresh milk and tear up the cheddar chesee slices in. 
2. Place saucepan over medium low heat and stir gently until all is melted and mixed in together. Set aside for 5 minutes to cool before use. 
3. Ladle big spoonful of the milk mixture into the egg yolks. Mix well and then add in the rest of the milk mixture in. Stir well. 
4. Sift in the cake flour and cocoa powder into the egg yolk mixture and make sure no lumps. 
5. Preheat the oven to 155 deg C with a water bath. 
6. Grease and line an 8x8 square baking pan. 
7. In another large mixing bowl, add the egg whites in and beat till foamy. Add in the sugar gradually and beat till stiff peaks. 
8. Gently fold in 1/3 of the egg whites portion into the cheese mixture. And repeat with the other 2 portions and careful not to deflate it.
9. Pour the batter into the prepared pan and smooth out the surface. 
10. Bake the cake in the oven for 50 minutes or till the tester comes out clean.
11. Chill the cake before serving.