Melt the butter in a saucepan over medium heat. Continue cooking until it turns golden brown and smells nutty. Remove from heat and let it cool slightly.

In a bowl, combine browned butter with granulated sugar and brown sugar. Add eggs and vanilla extract. Mix until smooth and glossy. In a separate bowl, combine flour, baking soda, baking powder, and salt. Fold the dry ingredients into the wet mixture until just combined. Do not overmix. Fold in the chocolate chips.

Preheat oven to 175°C (top & bottom heat).

Line a 23×23 cm baking pan with parchment paper. Spread the batter evenly into the pan. Bake for about 35 minutes, until the edges are golden and the center is just set. Do not overbake, they will continue setting while cooling. Let cool before slicing for clean cuts.