In saucepan, melt butter and chocolate. In bowl, beat eggs with sugar. Mix in melted butter and chocolate. Mix in dry ingredients and vanilla. Pour in 9x13 pan sprayed with Pam. Bake at 350 degrees for 18-20 minutes. Check for doneness with toothpick. Beat cream cheese and peanut butter. Beat in powdered sugar adding a little milk if necessary for creaminess. Ice brownies with mixture.