Heat oven to 350 degrees F. Coat a 15 x 10-inch jellyroll pan with a nonstick
Melt chocolate and butter in bowl over simmering water in saucepan. Stir until
Stir together flour, baking powder and salt in small bowl.
sugar, eggs, vanilla extract and chocolate-butter mixture in second bowl.
Spread in prepared pan.
Bake for 15 to 20 minutes or until dry-looking
on top and firm to the touch.
Meanwhile, prepare frosting.
Frosting: Combine sugar, milk, butter, chocolate and corn syrup in medium-size saucepan.
Bring to boiling over medium-high heat; cook 1 minute. Remove from heat. Stir in
vanilla extract. Cool to room temperature. Beat with a mixer until spreading
Cool brownies in pan on wire rack.
Spread evenly with frosting. Let stand until set, about 30 minutes.