Here's a simple recipe for pierogi dough that you can use to make both sweet and savory pierogi. The dough is vegan, so it works if you want to make vegan pierogi.
Mix the ingredients by stirring with a spoon. Be careful not to burn yourself. Once there is no visible water in the bowl, use your hands to knead the dough until it is a homogeneous ball.
Wrap and rest. Wrap the dough ball tightly in plastic wrap and let it rest for about 30 minutes before continuing.
Make pierogi. Once the wait is over, the dough is ready for rolling and making pierogi.
Notes
Double the dough. Since making pierogi takes quite a long time, I recommend doubling both the dough and filling to make a big batch that will be enough for at least two meals. You can freeze any leftover pierogi and have them ready when you are.
If you've been kneading the dough for a couple of minutes already and it's super dry and doesn't seem to take in any more flour, add a tablespoon or two of warm water.