A pączek is not a doughnut with a different name. The dough is enriched far past what a doughnut needs: whole milk, whole eggs plus extra yolks, real butter and sugar. That is what makes it dense and slightly chewy instead of light and crumbly, and it is why a pączek has no hole. There is no room for one.
The traditional Polish recipe also calls for a small amount of grain alcohol in the dough. It burns off in the fryer, and while it is there it keeps the dough from soaking up oil. That is the difference between a pączek that tastes clean and one that tastes greasy.
None of this is possible from a bag of mix, which is why we have never used one.