Sweetened condensed milk
Preheat oven to 350~. In large bowl, combine margarine, sugar, flour, cocoa, baking powder, eggs, milk, and 1 1/2 tsp vanilla. Mix well.
Spread in greased 13x9" pan. Bake 40 minutes. Just before brownies are done, in heavy saucepan, over low heat, melt chips with Eagle milk, and remaining vanilla. Remove from heat. Immediately spread over hot brownies. Cool. Chill, cut into bars. Store covered, at room temperature. 36-40 brownies.