This came about trying to find a good substitute for ricotta cheese in an Italian recipe that called for 400g ricotta; instead I used 200g creamy quark and 200g cottage cheese beaten well together. The layer of raspberry jam is my tweak on the original recipe. Worked really well!
Instead of quark, you can use Greek yoghurt.
If you don't have vanilla sugar, you can use 1/2 teaspoon vanilla extract and 2 teaspoons caster sugar.