Preheat your oven to 400°F (200°C) and grease your cookie sheets, or line them with parchment paper for easier cleanup.
In a large mixing bowl, sift together the flour, baking powder, salt, and baking soda. This step ensures your cookies bake up fluffy and light.
In a separate bowl, cream together the sugar and softened butter using an electric mixer. Keep beating until the mixture looks light and fluffy—this usually takes about 2-3 minutes.
Mix in the mashed bananas, eggs, and vanilla extract. The batter might look a little curdled at first, but that’s perfectly normal!
Gradually add the dry ingredients to the wet mixture. Stir gently to combine, but stop once no streaks of flour remain. Overmixing can make the cookies dense.
Fold in the chocolate chips, distributing them evenly throughout the dough.
Drop spoonfuls of dough onto the prepared cookie sheets, leaving about 2 inches of space between each to allow for spreading.
Bake for 12-15 minutes, watching closely toward the end. The cookies should be golden around the edges but still soft in the center.
Let the cookies cool on the baking sheet for a minute or two before transferring them to a wire rack to cool completely.