Preheat the oven to 350 degrees. Mix together brown sugar and margarine. Add egg and mix together. Add flour, salt, and 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 chocolate chips evenly over the top.
Return to oven for 1 minute. Remove and spread melted chips over the top.