Cheese is a basic ingredient used in pierogi. It is used to make sweet pierogi fillings as well as savory pierogi fillings.
I cover making a sweet cheese filling here. Potato and cheese, as well as other cheese fillings are covered in other videos. See the link below.
In all cases, these fillings start with a white cheese that is often called farmers cheese.
As you can see in the video, it has a very dry curd.
If you do not have white cheese, you can substitute cottage cheese provided that you drain it and squeeze it dry so that the curd is as dry as the cheese that you see in this video.
For a sweet cheese filling, add half an egg and a tablespoon or two of sugar to 250 g of white cheese. This makes enough filling for about 40 pierogi.
Beat the mixture until it is smooth.
Adjust the taste with sugar and by adding raisins or other fruits. If you add raisins, before you add them, be sure to soak them so that they are plump.
Note that a cheese filling should be very dry so that it can be handled during the pierogi filling process.
In fact this applies to all pierogi fillings. They should be dry.
And to make making pierogi easier, it is best to make your fillings the day before and put them in the refrigerator overnight to chill and get a bit more solid.
If you are making a sweet cheese pierogi, we recommend that you use a pierogi dough that is specifically designed to be very tender.
Likewise, be sure to roll your dough out very thin. People want the filling and not the dough. See How To Roll Out Pierogi Dough