Ingredients
Equipment
Method
- Preheat your oven to 350°F (180°C). Grease and line an 8-inch (20cm) non-stick baking pan. Leave the parchment extending over the sides to create a sling. You can secure it with binder clips if you like.
- Melt the butter in a medium saucepan over medium heat. Continue to cook, swirling the pan and whisking often, until the butter foams, turns golden brown, and has a nutty aroma. This should take about 3-4 minutes.
- Measure out 110g of the brown butter into a medium bowl. Let it cool for 15-20 minutes so it doesn't scramble the egg.
- Add the brown sugar and granulated sugar to the bowl with the brown butter. Mix to combine.
- Add the egg and whisk well for 1-2 minutes, or use an electric mixer, until the mixture lightens in color and thickens.
- Stir in the vanilla and mix well.
- Add the flour, baking powder, and salt. Mix with a rubber spatula until some flour streaks remain. This prevents overworking the dough.
- Add the chopped chocolate and mix to incorporate with the rubber spatula.
- Press the dough into the prepared pan, smoothing the top with an offset spatula. You can add a few extra chocolate chunks to the top if desired.
- Bake for 20 to 22 minutes, until the top is golden brown and set, and the edges begin to firm up. For crispier edges, bake a little longer.
- Remove the cookie bars from the oven and let them cool in the pan on a wire rack. Use the parchment paper sling to lift the bars out of the pan. Cut into pieces with a sharp knife.
- Store the cookie bars in an airtight container at room temperature for up to 3 days.
Notes
The recipe uses an initial quantity of butter, then a smaller amount of brown butter in the method. The larger initial amount accounts for water loss during the browning process. If you are scaling the recipe, note that pan sizes and cooking times in the method do not scale automatically; only the ingredient quantities in the list do.