Question: I have a recipe for some chocolate chip cookies, and it's near and dear to my heart. I watched my mom making these when I was little, and it's older than I am, being from her mom too. They're both gone now though, and I have no idea what's wrong. I have not changed anything. 

The ingredients are: 

* 1 cup sugar
* 1 cup brown sugar
* 2/3 cup butter
* 2/3 butter flavored Crisco
* 3 eggs
* 2 tsp vanilla
* 3 cups flour
* 1 tsp salt
* 1 tsp baking soda
* 2 cups chocolate chips

I've been making these for the past 10 years, since my mom couldn't anymore, and only the past few years I've noticed the changes. The cookies themselves are much puffier than they're supposed to be, and though they mostly taste the same, there's a weird bit of aftertaste to them that I can't place. I also just now realized that the dough is kind of oily almost, and not sticking together like I remember it doing before, but again, haven't changed anything. I'd post a picture, but for some reason it won't let me... 

I'd really like some ideas as to what I can do to fix these. They were something I loved helping my mom make when I was little, and it breaks my heart that I can't figure out what''s wrong with them.

Answer: 
This problem is happening to me. Got a recipe, used it successfully for a year or two, then suddenly they just stopped coming out amazing.

I put it down to me remembering the recipe wrong, the change of oven over that time and other factors.

Also, I notice that one batch can come out differently depending on what temperature I put them in at... If I refrigerate the batter for later cooking, they turn out much worse too. They're the same, but they are flakey. Flakey cookies? No thanks.

Try to forget the recipe, then do it all again adhering to the recipe written down as it is.

Your recipe looks fine to me. Sometimes the butter warming too much or melting creates an oily texture. I think you're like me, and you've forgot the timing and preparations BEFORE the cooking begins... it comes with a rushed life.
This has been mentioned already, but it's kind of hidden in among a bunch of other advice: I'm almost certain your problems are due to changes in the formulation of Crisco. Puffier than they used to be, almost oily in texture, and weird aftertaste all point to the shortening being the culprit.

One test to try might be to make the recipe with unflavored Crisco: if you still get the texture issues but without the weird aftertaste, I'd take that as proof.

The solution is probably to switch to an all-butter recipe, but if you want to stick to this recipe out of sentimental reasons, try replacing the shortening with lard: just from an ingredients standpoint, lard is closer to (unflavored) shortening than butter would be.