Baking advice

I've promised to bring cookies to an event on the 26th.  I'd like to bring at least 3 varieties.

I have time consuming food preparation and travel plans for the 24th, and will be visiting relatives for much of the 25th.

Does anyone have good recipes for freezer cookies, or desserts that taste best after sitting in the fridge for 4 days?  I'm almost certainly making brownies and bars in addition to cookies; advice on those is also welcome.