In a medium bowl, I whisked together the flour, baking soda, and salt. This helps evenly distribute the leavening agent. Setting this aside makes mixing easier later.
In a large bowl, I creamed the softened butter with both sugars until light and fluffy. This step adds air to the dough. It also ensures the cookies bake soft instead of dense.
I mixed in the mashed bananas, egg, and vanilla extract. The dough looked creamy and slightly loose. This is where the banana flavor really comes through.
I gradually added the dry ingredients into the wet mixture. I mixed just until everything was combined. Overmixing can make cookies tough, so I stopped as soon as no flour was visible.
Using a spatula, I gently folded in the chocolate chips. This helps keep them evenly distributed. Every cookie ends up with plenty of chocolate.
I scooped the dough onto a lined baking sheet, leaving space between each cookie. They baked at 350°F until the edges were set but centers still soft. Once done, I let them cool slightly before moving.