In a small bowl, stir together yeast and warm water. Let the mixture stand at room temperature for 10 minutes.
In a large mixing bowl, combine biscuit mix, the 1/2 cup water, and yeast mixture to form a soft dough. Divide dough in half. In a small bowl, stir together sugar and cinnamon.
Spray a 13x9x2-inch baking pan with nonstick cooking spray.
On a lightly floured surface, roll each portion of dough into a 12x10-inch rectangle. Brush with butter or margarine. Sprinkle with cinnamon-sugar mixture. Starting from a long side, roll up into a spiral; pinch seam to seal. Slice each roll crosswise into 1-inch pieces; arrange, cut sides up, in prepared pan.
Bake in a 375 degree F oven for 20 to 25 minutes. Cool slightly on a wire rack. Remove the rolls from pan. Drizzle with Powdered Sugar Icing, if you like. Makes 24 rolls.
In a mixing bowl, combine powdered sugar, milk or orange juice, and vanilla. If necessary, stir in additional milk or juice, 1 teaspoon at a time, until mixture drizzles easily.