In 2-quart saucepan, heat butter and 1 cup of the chocolate chips over low heat, stirring occasionally, until melted. Remove from heat; stir in sugar. Pour into large bowl. Beat in eggs one at a time until blended. Beat in vanilla. Stir in flour mixture until well blended. Stir in 1 cup of the chocolate chips and the cherries. Cover and refrigerate 30 minutes.