11 tablespoons (156g) unsalted butter
2 cups + 2 tablespoons (454g) light or dark brown sugar, packed
1 teaspoon salt
1 teaspoon vanilla extract
3 large eggs
2¼ teaspoons baking powder
½ teaspoon espresso powder, optional
2¾ cups (330g) all-purpose flour
2-3 cups (340-510g) chocolate chips
The original recipe calls for 3 cups of chocolate chips. I preferred this recipe with anywhere from 2-2½ cups. Since I know some of you will enjoy the full amount, I’ve listed a range in the recipe. You can also use a combination of chocolate chips and nuts, if desired.
If baking in a glass pan, bake at 325ºF and extend the baking time by about 10 minutes.
Heat the oven to 350ºF and lightly grease a 9 x 13-inch metal pan. You can also make a parchment sling by lining the baking pan with parchment, allowing excess to hang over the two long sides of the pan.
Melt the butter in a large bowl, then stir in the brown sugar, salt, and vanilla until well combined.
If the mixture is warm to the touch, allow it to cool slightly. Then add the eggs, one at at time, whisking well after each addition. Scrape the sides and bottom of your mixing bowl.
Add the baking powder, espresso powder, and flour. Stir well to combine. Then stir in the chocolate chips.
Scrape the batter into your prepared baking dish. Using a wet spatula or wet fingertips, spread the batter all the way to the edges. Smooth the top as best you can.
Bake for 30-32 minutes, until shiny and golden on top. A cake tester inserted in the center will NOT come out clean. The center may look quite undone at this point, but it will solidify as it cools. Remove the bars from the oven. If needed, use a spatula to flatten the edges.
Allow to cool completely, overnight is best. If you used a parchment sling, lift out the bars before cutting. Cut into bars and store in an airtight container at room temperature.