04Combine the flour, and the next 4 ingredients (through baking powder) in a large bowl, stirring well with a whisk.
05Combine 6 tablespoons butter, eggs, and 1 teaspoon vanilla extract.
06Add this mixture to the flour mixture,stir to combine.
07Scrape batter into a 9-inch square metal baking pan lightly coated with cooking spray.
08Bake at 350 degrees for 19 minutes, or until a wooden pick inserted comes out with moist crumbs clinging.
09Cool in pan on a wire rack.
10TO PREPARE TOPPING:.
11Melt 1/4 cup butter in a saucepan over medium heat.
12Add brown sugar, 1 1/2 tablespoons milk, and cook 2 minutes.
13Remove from heat, and add vanilla and powdered sugar, and stir with a whisk until smooth.
14Spread mixture evenly over cooled brownies,let stand 20 minutes, or until set.
15Combine remaining 2 tablespoons milk, and chocolate in a microwave-safe bowl, and microvave on high for 45 seconds, or until melted, stirring after 20 seconds.
16Stir just until smooth, and drizzle over caramel.
17Sprinkle with sea salt, let stand until set, and cut into 20 squares.