These is a krapfen recipe that is filled with homemade Italian pastry cream.
In a medium saucepan add milk and vanilla, bringing to a boil. Turn off heat and let sit for 10 minutes to cool just slightly on the burner.
In a large bowl, whisk together egg yolks and sugar until thick and pale.
Add the flour and whisk to well combine.
Gradually, in a steady stream, add the hot milk mixture to the egg mixture; whisking constantly until well combined.
Return the milk-egg mixture to the saucepan and cook over medium heat, whisking constantly, until thickened, about 3 to 5 minutes.
Remove from heat and strain through a mesh sieve. Discard any solids.
When pastry cream has completely cooled place in refrigerator to chill entirely.
Line a large baking sheet with parchment paper and lightly grease with oil.
In a large bowl, whisk together flours, sugar, instant yeast, vanilla, zest and salt in a large bowl.
Over stove over medium heat, bring milk to a low simmer, and then remove.
Make a well in the flour and pour in the warm milk.
Work together the milk and the dry ingredients gently with a fork.
Add the eggs all at once; work together the ingredients until you have a rough ball of dough.
Gradually add the butter, one-piece-at-a-time, working each piece of butter into the dough before adding the next.
Sprinkle flour onto a clean work surface.
Transfer to surface and knead until smooth and elastic (not sticky), 10 to 15 minutes.
Transfer dough back to the large bowl; cover with a sheet of plastic wrap and leave to rise in a warm place, 1 1/2 to 2 hours.
When the dough has doubled in volume, transfer to a clean, floured work surface.
Roll the dough out into a large circle that is 1 cm thick.
Use a 7 cm cookie cutter to create circles.
Gather up the leftover pieces, give a quick knead to bring the pieces together, return dough to the bowl, cover and leave to rise in a warm place until double in volume, about 1/2-hour and proceed to roll out and cut out rounds.
At this point if you have any remaining dough, gather together re-roll and cut rounds until all of the dough has been used.
Place the rounds onto prepared tray and cover with a sheet of plastic wrap and leave to rise in a warm place until doubled in volume and full of air, about 1-2 hours.
In a large heavy bottom pot or deep fryer, heat oil to 340F (170C).
Prepare a large plate with paper towel for cooked donuts.
Fry four to six at-a-time to ensure even frying. Fry until golden on both sides, 3 to 5 minutes.
Remove one-at-a-time, with a slotted spoon, drain on paper towels and immediately dust with sugar.
To fill, transfer pastry cream to a large pastry bag fitted with a 1 cm plain round tip.
Use a sharp paring knife to make a small hole (in the centre) on the top of each donut.
Insert pastry tip into the hole and pipe until they feel heavy.
Fill until a bit comes out the hole.
Serve that day for best results.
Extras can be stored airtight in fridge.