How can I make frosting without powdered sugar

Question

Milk Frosting. 1 and a 1/2 Cup Sugar, 1/2 Cup milk, 1 tsp Butter.
Put in a saucepan stirring constantly until it begins to boil.
Let boil with out stirring, until a few drops tested in cold water form a soft ball. Remove from heat.
Stir in 1 tsp of vanilla extract, then beat until it becomes a spreadable consistancy. If frosting becomes too stiff to spread, put in a double boiler over boiling water (a bowl on a pot of boiling water will work) it will melt, then beat again.