Funny you should mention ratio.
Michael Ruhlman - Ratio: The simple codes behind the craft of everyday cooking
Should give you most of what you need.
There is a great book called Ratio: The Simple Codes Behind the Craft of Everyday Cooking that covers the basic formulas for recipes so that you can then riff with confidence.
Yes, another chance to recommend Ratio
It might be just a different sensibility but I find cooking from principles and ratios far more useful than any cookbook. For example the salt fat acid heat approach is more like teaching you to fish while a recipe is giving you fish. Ratio cooking and baking is the same idea except you can apply it to the more exact practices of baking (or even home job chemistry really). When you know that pound cake is 1:1:1 flour:fat:sugar you can pretty much substitute anything you have around into that ratio and make something tasty. (i should say as a caveat i haven't read these books; they just express an approach to cooking that I take)
Mostly these kinds of books give you the principles to tap into the craft, creativity and artistry of cooking while recipes are specific. It's sort of like the difference between agile and cascade project management styles.
I'm not a great cook, but this is exactly what fascinates me about cooking.
I came across a book a few years ago, Ratio: The Simple Codes Behind the Craft of Everyday Cooking. Completely changed the way I look at food.
I still have problems with spices. Knowing the flavors, how they interact with each other, and the right amount to use.
As a side note: After many years of not keeping lard, I do now. It's amazing how easy making a pie crust can be, and the taste is so much better than pre-made. I'm really into savory pies at the moment. Been doing pot pies for a while, and just ventured into hand pies. And biscuits. And pancakes. So many different pancakes. Been playing with butter/lard substitution and at what point it impacts flavor.
And another side note: I used to have a good collection of old cookbooks. Not depression era, but self-published fund-raiser type cookbooks where you get all Grandmother's Old Recipes. Those are some interesting recipes. And they all turn out awesome. Unfortunately, I lost a whole box of them during my last move. I would love to replace them.