Grease 13x9x2-inch baking pan.
In a large mixing bowl, beat the butter for 30 seconds. Add the sugar and beat until fluffy. Add eggs and beat well. Stir in the chocolate syrup. Stir in the flour. (Batter will look curdled.)
Pour the batter into the prepared pan. Bake in a 350 degree F oven about 30 minutes or until a toothpick inserted in the center of brownies comes out clean.
Meanwhile, in a medium bowl, combine toffee pieces, chocolate pieces, and pecans. After removing pan from the oven, immediately sprinkle mixture evenly over top. Cool in pan on a wire rack. Cut into bars.