1-1/2 cups packed brown sugar
1/2 cup butter, melted
2 large eggs, lightly beaten, room temperature
1 teaspoon vanilla extract
1-1/2 cups all-purpose flour
1/2 teaspoon baking powder
1/2 teaspoon salt
1 cup semisweet chocolate chips
In a large bowl, combine the brown sugar, butter, eggs and vanilla just until blended. Combine the flour, baking powder and salt; add to brown sugar mixture. Stir in chocolate chips.
Spread into a greased 13x9-in. baking pan. Bake at 350° until a toothpick inserted in the center comes out clean, 18-20 minutes. Cool on a wire rack. Cut into bars.