Cream butter, sugar and cocoa; add eggs, one at a time, creaming well after each addition. Mix in flour, and vanilla. Pour into a grease a 9x13 inch pan. Batter is thick so you may have to spread it. (if you want your brownies thinner, use a bigger pan) Squeeze caramel in rows on top of the brownie mixture. With a knife swirl the caramel into the mixture, horizontal then vertical, but not all the way to the bottom of the pan. Bake at 350 for 25-30 min.