Chewy, Chunky Blondies

INGREDIENTS

• 2 cups all-purpose flour
• ¾ teaspoon baking powder
• ½ teaspoon baking soda
• ½ teaspoon salt
• 2 sticks (8 ounces) unsalted butter, at room temperature
• 1½ cups light brown sugar
• ½ cup granulated sugar
• 2 eggs
• 1 teaspoon vanilla extract
• 1 cup semisweet or bittersweet chocolate chips (or 6 ounces chocolate, chopped)
• 1 cup butterscotch chips
• 1 cup coarsely chopped walnuts
• 1 cup sweetened shredded coconut