what makes cookies cakey? too much eggs,or soda?

Answer 1

Eggs are used as a binder, and increase volume. You will notice on commercial brownie / cake mixes, for example, they offer directions for 'a more cake-like item' and suggest using another egg or two. So, I would believe that would be enough to conclude that it is the eggs that take 'chewy, gooey and yummy', to more cake-like.

Answer 2

It's possible for both, as they can both do that,

However, eggs are moister, so it tends to moisten up the cookies to a cake form.

Answer 3

soda dude - not so much