4. Replace your parchment paper after each batch. Reusing parchment paper is more likely to result in burnt and sticky cookies.
It’s better to change it after each baking cycle.
5. Consider your particular type of puff pastry.
For example, cookies may bake faster if you choose a butter puff pastry.
6. Don’t forget to refrigerate the rolled pastry. Once you roll your pastry, refrigerate it before cutting it into cookies.
The recipe says 5 to 10 minutes. However, I usually leave mine in longer.
The longer they stay in the refrigerator (up to about 30 minutes), the easier they are to cut.
You don’t want to flatten the pastry while cutting the cookies. Refrigeration is the best way to ensure that.
How to Store Palmiers
Let’s assume you make extra palmiers or have leftovers, which is unlikely!
In any case, you need to know how to store them. Fortunately, it’s simple.
Place them in an airtight container or a Ziploc bag with as much air removed as possible.
Then, store them at room temperature, not in the refrigerator.
The refrigerator can extend their shelf life, but it ruins their texture.
It makes them soft and sticky. Keeping them at room temperature will keep them crispy and crunchy.
They should last for about 3 to 4 days at room temperature.
(As long as your container is truly airtight.)

Can I Freeze the Cookies?
Some people claim you can freeze baked palmier cookies.
I’ve never had luck with that, though. Every time I try to thaw them, they completely lose their texture.
Therefore, I do not recommend freezing them once they’re baked.*
However, pre-baked dough freezes beautifully.
You can freeze the entire roll of dough or slice the cookies and freeze them.
When you want to bake them, you can do so from frozen. Just slice them if they aren’t already.
Then, bake them for about 2 to 3 minutes longer than you would with thawed dough.
*Note: If you do want to freeze baked cookies, let them cool completely first. Then, layer them in a freezer-safe container, making sure to add parchment paper between each layer.
Label and store them in the freezer. I’m not sure how long they’ll last, as I’ve never had the chance to freeze them myself. I wouldn’t keep them for more than a month or two, though.

