Beat butter and brown sugar until smooth, add egg and vanilla beat until light and fluffy. Stir in flour, baking soda and salt until well blended.
Stir in chip.
Spread in greased 9" x13" cake pan, Bake at 350F for 35 to 40 min, or until toothpick inserted in center comes out clean.
Sprinkle chocolate chunks over top. and return in oven for 1 minute to melt chocolate
Spread chocolate evenly over surface.
Sprinkles with pecans. Cool, cut into bars
Chocolat chunks will hold their shape
after being in the oven for 1 minute but will be soft all the way through.'
Spread with a spatula or knife to make fancy pattern