Preheat the oven to 350 degrees. Mix together 1 cup brown sugar and 1 cup butter. Add 1 egg and continue mixing until combined. Add 2 cups flour, ½ teaspoon salt, and 1 teaspoon vanilla, and mix together well.
Spread dough onto a cookie sheet to a thickness of ¼ to ½-inch.
Bake for 15 to 20 minutes, or until slightly brown. At this point, pull out of the oven and sprinkle 6 ounces chocolate chips evenly over the top.
Return to oven for 1 minute. Remove and spread melted chips over the top.