I have tried to do cakes many times and I frequently have the problem of my cake not having the bubbly structure I expect, but rather looking like a smooth mass on the inside.
So far I have attributed this to user error, but after my mom also had the same problem I am starting to think if it may be the oven?
What I have noticed is, that I have to frequently bake longer than the recipe suggests until the fork comes out dry. However, when using a thermometer the temperature seems to be generally OK in the oven, although it does seem to fluctuate a bit (+-5°C).
This is what my last iteration looks like:
What I expect is something like this, a structure with many bubbles:
Best Answer
This is a very vexing case, I douobt that anybody can tell from looking at your cake. So you will have to troubleshoot it yourself by first trying to bake a successful cake by following a traditional recipe and using best practices, and then, if that cake works well, start changing it back towards your preferred recipe one-by-one and seeing what makes the difference. For the test cake, you should bake a very standard recipe that has the best chances of rising well - I'd say that's a pound cake.
So, use following factors:
If that works, as I said above, you will have to slowly change the ingredients back to your preferred recipe and see when the change happens.
If it isn't work even for that, there is some hidden factor that is very difficult to guess at. You will probably have to ask a good baker to bake together with you and either show you how they bake, or have them watch how you bake, and see if that person can spot the problem. You can also have them bake in your kitchen and with your oven, to see if they get the same trouble - but if you measured your oven's temperature, there isn't much that can be going wrong there.