Salted Caramel Brownies

INGREDIENTS

• 3.38 ounces all-purpose flour (about 3/4 cup)
• 1 cup granulated sugar
• 3/4 cup unsweetened cocoa
• 1/2 cup packed brown sugar
• 1/2 teaspoon baking powder
• 6 tablespoons butter, melted
• 2 large eggs
• 1 teaspoon vanilla extract
• Cooking spray
• 1/4 cup butter
• 1/4 cup packed brown sugar
• 3 1/2 tablespoons evaporated fat-free milk, divided
• 1/4 teaspoon vanilla extract
• 1/2 cup powdered sugar
• 1 ounce bittersweet chocolate, coarsely chopped
• 1/8 teaspoon coarse sea salt