Step 1: Prep the Pan
Preheat oven to 350°F. Line a 9×13-inch baking dish with parchment paper, leaving extra on the sides for lifting. Lightly grease the parchment and pan edges.
Step 2: Cream Butter & Sugar
In a large bowl, beat butter and brown sugar with an electric mixer on medium for 2 minutes until light and fluffy.
Step 3: Add Wet Ingredients
Mix in eggs, vanilla, salt, and baking powder until smooth. Scrape down the sides to ensure everything is evenly combined.
Step 4: Fold in Flour & Chocolate
Lower mixer speed and gradually add flour, mixing just until combined. Fold in chocolate chunks and chips with a spatula. Avoid overmixing to keep bars tender.
Step 5: Bake
Spread batter evenly in the prepared pan. Bake for 30 minutes. The edges should be set and golden while the center remains slightly soft.
Step 6: Cool & Slice
Let cool 5 minutes in the pan. Lift out using the parchment overhang and place on a wire rack to cool completely. Cutting once fully cooled gives clean, even squares.
