In a large bowl, combine biscuit mix and milk. Turn onto a floured surface; knead 8-10 times. Roll the dough into a 12-in. x 10-in. rectangle. Spread with butter. Combine the sugar, cinnamon and raisins if desired; sprinkle over butter.
Roll up from a long side; pinch seam to seal. Cut into 12 slices; place with cut side down on a large greased baking sheet.
Bake at 450° for 10-12 minutes or until golden brown. Meanwhile, combine the icing ingredients; spread over warm rolls. Serve warm. Yield: 1 dozen.