CHOCOLATE-CHIP STREUSEL BROWNIES

Steps:

• Cookie Dough:Preheat oven to 350 degrees. Brush a 9-by-13-inch baking pan with butter; line with parchment, leaving a slight overhang on long sides. Whisk together flour, baking soda, baking powder, and salt.
• In a large bowl, beat butter with both sugars on medium-high speed until light and fluffy, 6 minutes. Reduce speed to medium-low and beat in egg. Beat in vanilla. Reduce speed to low and add flour mixture; beat until just incorporated. Stir in chocolate.
• Brownie Batter:Melt butter and chocolate in a medium heat-proof bowl set over (not in) a pot of simmering water, stirring until smooth. Remove from heat; whisk in granulated sugar. Whisk in eggs, one at a time, until combined. Whisk in cocoa and salt. Fold in flour until combined.
• Pour brownie batter into prepared pan, smoothing top with an offset spatula. Crumble cookie dough evenly over batter. Cover with parchment-lined foil; bake until just set, 20 minutes. Remove foil and continue baking until golden brown and a toothpick inserted into center (avoiding chocolate chunks) comes out with moist crumbs, 27 to 30 minutes more. Let cool completely in pan on a wire rack. Lift brownies from pan using parchment; cut into 16 squares. Brownies can be stored in an airtight container at room temperature up to 3 days.