Pre-heat the oven to 425° F.
In a small mixing bowl, mix together the sugar and cinnamon.
In a separate large mixing bowl, add the cinnamon sugar, biscuit mix, and water. Mix everything together well.
Drop the biscuits onto an un-greased baking sheet, about 1 to 2 inches apart.
Bake at 425° F for 8 to 11 minutes (oven times may vary), until the biscuits turn golden brown.
Meanwhile, mix up the icing in a large mixing bowl, combining the softened butter, vanilla extract, powdered sugar, and milk.
When the biscuits are done, remove them from the oven. While they're still hot, brush on the icing, and let it melt into each biscuit.
Serve immediately while warm.