1 package yeast
1 cup warm milk
3 3/4 - 4 1/4 cup flour
3/4 cup butter or margarine, softened
6 tablespoons sugar
1 teaspoon salt
3 eggs
1 egg yolk

Dissolve yeast in warm mile in a medium sized bowl.  Add 1 3/4 cups flour and mix thoroughly. Cover bowl with plastic wrap and allow mixture to rise 45 minutes.

Place butter, sugar and salt into a bowl and cream them together. Add eggs and one egg yolk, one at a time, beating well after each egg is added. Add 1 3/4 cups flour and mix until well blended. Add sponge and mix well. Add remaining flour and knead . Place dough in a greased bowl and turn to grease top. Let rest until double in size.
Punch dough down. Cover bowl with plastic wrap and refrigerate at least 4 hours or over night.

Punch dough down, Shape into 3 large or 24 small individual brioche. work quickly as dough will become sticky and difficult to handle as it warms to room temperature. Place in grease fluted brioche pans. Cover; let rise at room temperature, until doubled in size.

Bake at 375 degrees for 20 to 25 minutes for a large loaf or 10 to 15 minutes for individual loaves. Remove from pans immediately and brush all surfaces with cooking oil or shortening.