Whole-Wheat Brownies

INGREDIENTS

• 6 tablespoons (3/4 stick) unsalted butter, melted, plus more for pan
• 1/2 cup all-purpose flour, (spooned and leveled)
• 1/2 cup whole-wheat flour (spooned and leveled)
• 1/3 cup unsweetened cocoa powder
• 1 1/4 teaspoons baking powder
• 1 teaspoon coarse salt
• 1/4 teaspoon baking soda
• 1 cup packed light-brown sugar
• 1 1/4 cups unsweetened applesauce
• 1 large egg
• 8 ounces semisweet chocolate, coarsely chopped