Storing Self-Made Cookies/Brittles/etc longer: ingredients and techniques

Question

I like to make a large amount of pan sheet cookies or brownie brittles as something to crumble over my breakfast yogurt. Something in the style of variations on the following recipe: https://www.instagram.com/p/CENLDHlJTp-/?epik=dj0yJnU9aWNEWTNma0ZEdVZsUjN2X2tVd2hSa1BvUVNtZXlBVUkmcD0wJm49V0ZxTlJMakQycmcwWUFWTzBtclZRdyZ0PUFBQUFBR0NYMGZB

I let the brittle bake for fairly long, and let it cool and harden over the entire day so that it has no moisture left. Then I store it in a closed glass container in a shelf at room temperature.

They keep fairly well but after 2-3 weeks, a tiny bit of mold starts to form, faster than I can eat them. Any ideas on how I could keep it longer? Ideally, they would store for up to 4 weeks.

Any other techniques or additional preservatives I could add?

Answer 1

I would freeze it. Crumble will defrost pretty much instantly when you take it out of the freezer, so you can just pour it straight from the freezer container onto your yogurt. If you freeze it on a tray and then dump it into a container, it should stay crumbly rather than freeze into a block so it's easy to handle.

Answer 2

Freeze them and they should last much longer; wrap them tightly in plastic wrap or foil to avoid freezer burn.

Answer 3

Freezing is easiest but just for novelty's sake:

Mold needs oxygen.

To remove oxygen from glass jar filled with enough room to perform this stunt, a little pure alcohol set alight and lid quickly replaced, should do the trick. Alcohol rubbed on upper glass, not allowed to drip.

Test on empty jar first as too much alcohol would burn off O2 leaving moisture. Too little leaves O2.