Put yeast and sugar in bowl add the warm water and let sit for 10 minutes.
In a bowl, measure out the flour, second amount of sugar and the salt. Cut in the butter using a pastry blender. The mixture should be well blended.
Place milk in a liquid measuring cup or bowl and microwave for about 45 seconds to warm it up.
Add the slightly beaten egg to the milk.
Add in the yeast mix and the milk and egg mixture, into the dry ingredients.
Stir until it's well blended. The end result is a cross between a batter and a kneadable dough. Don't add more flour.
The dough will increase in size a bit, so make sure your bowl is larger than the mound of dough.
Cover the bowl in plastic wrap and then refrigerate for at least 4 hours or overnight.
After the dough has chilled sprinkle flour on your counter.
Roll the dough out to 1/2 inch thickness. The dough will be sticky, but it's easiest to work with when it's cold, so don't remove the bowl of dough from the fridge until your ready to use it.
Use a pizza cutter to slice 3/4 inch strips. Twist them, starting at one end and then roll it up into a circle.
Put the twists onto a greased pan. Let rise for about an hour or until doubled in size. (I turn my oven on to preheat for about 2 minutes, then turned it off. I let my rolls rise in the warm oven.
After the dough rises, add the toppings of choice.
Bake at 350 for about 10-15 minutes. Watch carefully for browning after about 7-8 minutes, if they're getting too brown, place some foil over the top. (Just lay it there, don't tuck in edges or anything).
Make a powdered sugar icing by mixing 1 cup of icing sugar, 1/2 teaspoon of vanilla and enough milk to make a spreadable consistency. Drizzle over butterhorns as desired and enjoy!