Chocolate Cream Filled Vanilla Sugar Doughnuts

1 (1/4-oz) package active dry yeast (2 1/2 teaspoons)
2 tablespoons warm water (105–115°F)
3 1/4 – 3 3/4 cups all-purpose flour plus additional for sprinkling and rolling out dough
1 cup whole milk, at room temperature
1/4 cup (1/2 stick) unsalted butter, softened
3 large egg yolks
2 tablespoons sugar
1 1/2 teaspoons salt
1/4 teaspoon cinnamon

For the Vanilla Sugar:

1 1/3 cup granulated sugar
1 vanilla bean, scraped
two pinches salt

For the Chocolate Pastry Cream:

4 large egg yolks
1/4 cup granulated sugar
2 tablespoons cornstarch
3 tablespoons cocoa powder
1/4 teaspoon salt
1 cup whole milk
3 ounces bittersweet chocolate, cut into small chunks
2 tablespoons unsalted butter
1 teaspoon pure vanilla extract

About 6 cups vegetable oil for deep frying, you’ll need about 3 to 4-inches deep for frying

To Make the Doughnuts and Vanilla Sugar:

Stir together yeast and warm water in a small bowl until yeast is dissolved. Let stand until foamy, about 5 minutes. (If yeast doesn’t foam, discard and start over with new yeast.)

In the bowl of an upright stand mixer fitted with a dough hook, mix together yeast mixture, flour, milk, butter, yolks, sugar, salt, and cinnamon.  Beat at low speed until a soft dough forms. Increase speed to medium-high and beat 3 minutes more.  The dough will be soft and sticky.  If you’s too sticky to handle, add up to 1/2 cup more flour.  Note:  the doughnut dough should be soft and somewhat sticky so don’t add too much flour.

Scrape dough down side of bowl (all around) into center, then sprinkle lightly with flour (to keep a crust from forming). Cover bowl with plastic wrap and a clean kitchen towel.   Let dough rise in a draft-free place at warm room temperature until doubled in bulk, 1 1/2 to 2 hours. (Alternatively, let dough rise in bowl in refrigerator 8 to 12 hours.)  This is a great time to make the Chocolate Pastry Cream (instructions below).

Turn dough out onto a lightly floured surface and roll out with a lightly floured rolling pin into a 12-inch round (1/2 inch thick). Cut out as many rounds as possible with 3-inch cutter and transfer doughnuts to a lightly floured large baking sheet. Cover doughnuts with a clean kitchen towel and let rise in a draft-free place at warm room temperature until slightly puffed, about 30 minutes (45 minutes if dough was cold when cutting out doughnuts). Do not reroll scraps (they’ll make for tough doughnuts).  While the cut doughnuts rise, make the Vanilla Sugar.  In a medium bowl, combine sugar, vanilla bean scrapings, and salt.  Use your fingers to make sure the vanilla bean scrapings are evenly disbursed throughout the sugar.  Set aside.

Heat 2 1/2 inches oil in a deep 4-quart heavy pot until it registers 350°F on thermometer. Fry doughnuts, 2 at a time, turning occasionally with a wire or mesh skimmer or a slotted spoon, until puffed and golden brown, just over 2 minutes per batch (about 1 minute per side).  Before removing the cooked doughnuts from the oil, quickly submerge them in the hot oil then immediately remove and place in the Vanilla Sugar mixture.    Toss in the sugar and them allow to cool on a paper towel lined baking sheet.

Return oil to 350°F between batches before frying each pair of doughnuts.

To Make the Chocolate Pastry Cream:

In a medium saute pan, whisk together egg yolks, sugar, cornstarch, cocoa powder, and salt.  The mixture will be fairly thick.  Slowly whisk in the milk.  Place pan over medium low heat and slowly heat.  Stir near constantly so that the milk does not burn and the eggs do not cook.  When mixture just comes to a boil it will quickly begin to thicken.  Remove from heat and continue whisking until thick and smooth.  The mixture will be the consistency of cold pudding.  Add chocolate chunks, butter, and vanilla extract to the warm chocolate mixture and stir until all is melted and well incorporated.  Transfer hot pastry cream to a small bowl and cover with plastic wrap so the plastic wrap touches the surface of the cream.  Chill for about 2 hours.

To Fill the Doughnuts:

Doughnuts will already be coated in Vanilla Sugar before they’re filled with Chocolate Pastry Cream.  Try to handle the doughnuts carefully, as to not knock off all of the sugar coating.  Using the slender handle end of a spoon, create a hole in the side of each doughnut.  This is where our pastry tip will go.

Fill a small pastry bag, fitted with a medium round tip, with Chocolate Pastry Cream.  Twist to seal the bag.  Carefully lift a doughnut and insert just the tip of the pastry tip into the doughnut.  Squeeze pastry bag until doughnut feels just full.  Imagine that you’re filling each doughnut with about 2 tablespoons of Chocolate Pastry Cream.  Add too much pastry cream and you’ll know it.  The cream will ooze out a bit.  It takes just a bit of practice finding the right amount.

Fill each doughnut.  Serve immediately or cover doughnuts for later serving.  These doughnuts are best served the day they are made.  They should be refrigerated after about an hour at room temperature, just to be safe.