Heat the milk to 180 degrees (*scalded milk), then cool to 90 degrees.
Place the sugar and yeast in a small cup and mix well.
When the milk is around 90 degrees F, put in the sugar/yeast mixture.
Set the milk aside until it begins to bubbles.
Place the flour and the salt in the bowl of a stand mixer.
Melt the butter and set aside. Beat the egg with a whisk, then pour the butter (cooled) into the egg and whisk it well.
Using a dough hook, pour the milk into the flour mixture. Then pour in the egg/butter mixture.
When the dough forms a dough ball and leaves the sides of the bowl, remove to a floured flat clear surface and knead until the ball is shiny and springy.
Place the dough ball in an oiled bowl and into a proofing box. Let it raise until double in size.**
Remove the dough ball from the bowl and punch down.
Roll out the dough to 1/8-1/4 inch thick. You can use a pasta machine for this.
Form the Estiffras into half moons, squares or triangles. I used a ravioli maker.
Add the filling, see below.