Boston Cream Donuts

Combine the yeast with the flour.
In the bowl of the stand mixer fitted with the paddle attachment combine the shortening, sugar, salt, and milk powder and mix until well combined. Do not whip until light.
Add the eggs gradually.
Add the water and mix briefly.
Switch to the dough attachment and add the flour and yeast. Mix until fully developed, approximately 6-8 minutes on second speed.
Move the dough to a lightly greased bowl and cover the top of the bowl with plastic wrap. Bulk ferment for 1½ hours at 80℉.
Punch down the dough and turn out onto a floured surface. Roll the dough to ½ inch thickness. Cut out with round cutters. Place the rounds onto squares of parchment paper and proof for about 45 minutes or until 1 in. tall.
Fry the donuts at 360℉ for 1-2 minutes on each side. Lift them from the fat and let the excess fat drip off. Place the donuts in one layer on paper towels to cool completely.

In a medium saucepan, dissolve the sugar in the milk and bring just to a boil.
With a whisk, beat the egg yolks and whole eggs in a stainless steel bowl.
Combine the cornstarch and sugar. Add to the eggs and whisk until smooth.
Temper the egg mixture by slowly beating in hot milk.
Return the mixture to the heat and bring to a boil, stirring constantly.
When the mixture comes to a boil, continue to stir constantly and boil for up to 2 minutes, until the cream has no raw starchy taste.
Remove from the heat. Stir in the butter and vanilla. Mix until butter is melted and completely blended in.
Pour out into a clean shallow pan. Cover with plastic wrap placed directly in contact with the surface of the cream to prevent a crust from forming. Chill.
For filling donuts, whip the chilled pastry cream until smooth before using.

In a medium saucepan, scald the heavy cream.
Pour hot cream over the chocolate and let sit for 3 minutes.
Stir the mixture until cream is fully mixed in and the mixture is completely smooth.