1) For filling, whisk eggs with sugar in a medium bowl until they are nice and light. Then whisk in flour and cornstarch. In a medium sauce pan, combine milk, cream, and vanilla bean (scraped). Heat over medium-low heat until it’s just simmering.
2) Carefully whisk hot milk mixture into egg mixture, working with a bit of liquid at a time to slowly bring up temperature of eggs. Once both mixtures are combined, stir in extract and return everything to sauce pan.
3) Cook over low heat, stirring constantly, until mixture thickens, about 2-3 minutes. You can store this in the fridge for a few days. Place plastic wrap right on top of filling so a film doesn’t form.
4) To make donuts, combine milk and water in a mixing bowl. Add yeast and let sit for 5 minutes until yeast foams.
5) Add all other ingredients, flour last, and mix with a dough hook until dough forms a soft, but not sticky ball. If it’s sticking to the bowl, add more flour. If you don’t have a mixer, you can just use a wooden spoon.
6) Dust dough with flour and let rise for 2 hours or until it doubles in size.
7) Roll out dough on lightly floured surface into a 12×18 rectangle. Slice into 12 even rectangle pieces. Let pieces rise for 15 minutes or so.
8) Fry donuts at 350 degrees for 2-3 minutes per side. You’ll have to flip them because they float. Remove donuts to drain on a paper towel or on a wire rack.
9) For glazes, mix liquids in a saucepan over low heat until hot. If you’re using chocolate, melt it in pan. Then whisk in powdered sugar until glaze is thick, but pourable.
10) To fill donuts, use a long narrow knife to hollow out a cavity. Then pipe in filling using a pastry bag. It’s helps to have a helper for this part.
11) Dip donuts in glaze after they are filled (or you can skip the filling). Let glaze harden for a few minutes. Eat as soon as possible!