How can I bake my cakes without so many air holes in it? Could it be my oven or do I need the heating strips?

I tap mine against the counter a few times so that the air comes to the top and is allowed to escape before I put my cake in the oven.

Same as above, I 'drop' mine 2-3cm onto the bench in their pan and it pushes the bubbles to the top.

Thank you for the tips..I just put one in the oven that I did as suggested...