Mix the protein powder with water and almond milk until you achieve smooth and pudding-like consistence. 

Beat egg whites (in a separate pot).

Add lean curd cheese into a separate (bigger) bowls where you will be mixing all the ingredients.

Now add yolks, protein powder pudding, erythritol and vanilla extract.  Mix the ingredients with a fork. 

Next add egg whites and mix again. This time you can use a mixer. 

Pour about 1/4 of your protein cheesecake dough into another pot to prepare the cheesecake bottom. Add 15 g of cacao powder and blend it. 

Spread the calorie-free baking spray onto the baking form. 

Pour the cheesecake bottom into the form and spread it evenly. 

Now pour the rest of the cheesecake dough. Sprinkle it with cacao powder. 

Bake for about 50 minutes at 170 °C or 340 °F. Your cheesecake should grow nicely. 

After about 50 minutes you can take your cheesecake out of the oven and let it cool down. 

Your protein cheesecake will taste the best the next day after spending one night in the fridge.