Add 3 packages of yeast to warm water and 3 tsp sugar
Scald milk, and add butter to milk. Let sit until butter melts.
Add yeast mixture to milk and butter mixture.
Add vanilla, salt, 4 cups flour, 7 egg yolks, and 2 cups of sugar. Whip and let rise.
Add 6 cups flour (more may be needed) and egg white. Knead and let rise.
Grease coffee cans with wax (parchment) paper on bottom.
Fill can 1/3 full of dough and let rise.
Bake at 325°F for 45 minutes to 1 hour.
Let sit for 5 minutes, then hit lightly on sides of can to remove.
Frost and decorate.