**These can be difficult to keep closed while baking. It's important to give the two ends you are bringing together a good pinch to keep sealed. Adding a bit of water or egg wash will also act as a glue to hold it together as well.
Kolaczki are best eaten the same day or within a day or two. Dust with powdered sugar just before serving.
These can be frozen unbaked. Fill them and freeze on a parchment-lined sheet pan. When completely frozen, transfer to a freezer-safe container separated by sheets of parchment paper.
Bake them from the frozen state. You will need to bake longer than the 15 minutes though.
Don't freeze baked kołaczki. When defrosted, they will be soggy.