I tried two brownie recipes and both of them were too spongy, what did I do wrong?

I tried these two recipes 1 & 2. I did not add chocolate chips / chunks of chocolate, everything else was the same. I baked both at 180c for about 20 minutes, now I'm wondering if I overcooked them. I also feel 2/3 cups of cocoa powder was too much, which the first recipe called for. So, how do I make a more gooey brownie?

bon appetit