If you really want to do this, you have to become a pedagogue first and train yourself in cooking second. This involves:
- Decide which specific skill you want to work on. Example: judge the doneness of pie crusts.
- Read the theory on the subject. Yes, there are books which explain how pie crusts work.
- Assess how far you are in your current skill. How frequently are your pie crusts done well?
- Seek for recipes which will require you to use that skill. Since you've read the theory, you are aware which set of recipes will need to cover in order to gain the skill. For pie crusts, you'll probably want to exercise simple flaky, simple shortbread, "wet" shortbreads (with egg, alcohol, and other liquids), crusts started from frozen, and crusts containing ingredients which change the browning behavior (soda, vinegar, sugar).
- Make these recipes until you are getting consistently good results.
- Document your cooking, noting what went wrong, and exercising that part more.
Of course, you will have a bit of trouble, because self-teaching does require some bootstrapping. As a novice, it is especially hard to properly decide what is a single skill and what is a combination of many skills, and also which situations are important to train for a skill. But it can be done, and done successfully.
This is known as "deliberate practice" and is the normal way to become an expert in a field, so that in 20 years, you will have 20 years of experience and not one year of experience, repeated 20 times.
If you are thinking "this is a lot of effort, I don't want to do it", I agree. Most people don't need to become cooking experts, and following the above regimen is quite superfluous for them. They do as Jefromi suggested, cooking whatever they like, and soaking up whatever nugget of cooking knowledge they notice along the way. So slowly, they become better cooks.
So why I am writing all this? Because this is what you asked for. Specifically, this is the way to avoid making recipes which are neither so easy that you teach you nothing, nor so hard that you fail to realize what they are teaching you, or even simply mess them up. You can either consciously organize an effective learning process for yourself and have an effective learning process, or simply cook with the side effect of learning now and then. It's your decision which you choose, the restriction is simply that, unless you pay a personal cooking coach, you can't have it both at once.