Kolaczki are rich and flaky, pastry-like cookies filled with jam. These are traditional Polish cookies, although styles, recipes and name spellings may vary across other regions. They are a great cookie for holiday baking and special events. All you need is 5 simple ingredients and a bit of time!
A common problem with using jam for the filling of these cookies is that the jam melts and spreads all over the cookie when it bakes.
There are two reasons why this happens. The cookies either get overfilled or the jam is too thin and runny to hold up to the heat of the oven.
Using pastry filling is actually best and recommended. Pastry filling is already thickened and can withstand the heat in the oven.
If you don’t have pastry filling on hand, the next best thing is fruit spread or whole fruit preserves. I tested this and it holds up a bit better than regular jam without having to thicken it yourself.
If using a standard jam, then you will need to cook it down for a few minutes in a pot to thicken, before adding it to the unbaked cookies. This will help avoid a jammy mess and keep your cookies looking pretty & perfect!
I also tried cooking jam with corn starch to thicken it, but I did not prefer the texture. After baking with the cookies, the corn starch version was a bit gummy and leathery.
Do NOT use regular jelly for this recipe. It will melt and burn in the oven!
Keywords: Kolaczki, Polish Cookies, Polish Desserts