Preheat oven 350, grease and flour a 9x13 pan. In a large bowl, cream butter and brown sugar until well blended. Beat in eggs and vanilla. In another bowl, mix the flour, baking powder and salt, gradually beat into creamed mixture. Stir in cinnamon chips. Spread into prepare 9x13 pan. Sprinkle with the cinnamon/sugar. Bake 20 minutes, test until toothpick inserted in center comes out clean. Cool. Glaze: In a small bowl, mix all ingredients until smooth, drizzle over top. Cut into bars, serve.