Why does my cake lack air bubbles and looks like a molten mass?
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: 


200 g eggs (4 whole eggs), 200 g white all purpose flour, 200 g sugar, 200 g cow-milk butter, 10 g baking powder (not baking soda!). Do not make any replacements here, and don't add other ingredients (flavors, etc.) 
make sure the ingredients are all room temperature, and have gotten there slowly. Just leave them overnight, no "Oh I forgot the butter in the fridge, I'll give it 15 seconds in the microwave". 
use the creaming method. Cream the butter and the sugar together until you see an obvious change in color and volume (can take 10+ minutes), then add the eggs and beat well, only then add the flour and baking powder. 
Use freshly bought baking powder 
sift the flour
bake in a 175 C oven for as long as it takes to pass the skewer test. 


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.