"Candy" Bars

Preheat oven to 375 degrees F. Spray 13- by 9-inch metal baking pan with nonstick baking spray; line pan with foil, then spray foil. With mixer on medium-high speed, beat butter, brown sugar and salt until creamy. Beat in egg and vanilla. With mixer on low speed, beat in flour until just combined. Transfer to prepared pan. With lightly floured hands, spread into even layer. Bake 25 to 30 minutes or until deep golden brown around edges. Cool completely on wire rack. Spread crust with caramel sauce. Top with toffee bits, broken pretzels and toasted coconut. Drizzle with melted bittersweet chocolate. Chill to set (1 1/2 hours). Cut into 2-inch squares.