Let the dough rest in the bowl covered for about 20 minutes. Transfer to a lightly oiled bowl and cover with plastic wrap and refrigerate for at least 8 hours or overnight.

When you are ready to make your donuts on the next day, remove dough from the fridge and roll it out on a lightly floured counter until it is about 1/2 inch thick. Cut with round 3” cutters at whatever size donuts you prefer. If you want to make filled donuts, ie this recipe for pistachio filled donuts, don’t cut a hole in the middle but if you do want to make traditional donuts, cut a hole in the middle with a 1/2 inch round cutter.

Place donuts on a baking sheet lined with parchment paper and lightly oiled. Let them rest covered for about 40 minutes until they rise.

To fry you are going to need about 4 cups of vegetable shortening or oil, heat it up in a large heavy bottom pan until it registers 350F. Fry the donuts 2 or 3 at a time, depending on the size of your pan, for about 1 minute on each side or until golden brown. Remove donuts from the oil and let them drain on a tray lined with paper towels.

Bring milk and chopped pistachios to a boil in a medium sauce pan. As soon as you see the milk coming to a boil, turn the heat off and set the milk aside to let the mixture steep for 20 minutes. The milk will become infused with the pistachio flavor.

Whisk egg yolks and sugar in a medium bowl until pale in color, for a couple of minutes. Add cornstarch and whisk to combine.

Add 1/3 of the milk mixture to yolks while whisking. After this first 1/3 was incorporated, add the rest of the milk. Whisking constantly. Return this mixture back to the pan where you boiled the milk. Bring it to the stove, over medium heat and stir with a wooden spoon while cooking the mixture. Bring it to a boil while stirring. Stir vigorously and fast, so you don’t let the custard stick to the bottom of the pan. It will take just a couple of minutes after the mixture has come to a boil to thicken. At first it will seem lumpy, but give it a chance, keep stirring until it’s smooth and thick.

Mix the confectioners sugar, milk and vanilla until smooth. Make sure the glaze is the right consistency, it should fall slowly from the spatula. If you feel like it’s too runny, add some more powdered sugar by the teaspoon, if you think it’s too thick, add some more milk, by the teaspoon.

Cut a 2 inch slit in the middle of the donut crosswise so you can stuff it with the pistachio custard. Don’t cut it all the way. You just want enough room to be able to stick a teaspoon full of filling in the donut.

Pour glaze onto a shallow bowl. After filling each donut with about 1 teaspoon of filling, dunk the top surface in the glaze and pull donut up and let it rest on top of a wire to let the glaze drip. When dunking the donuts (Haha) in the glaze, it helps to kinda twist the donut right before pulling to make it easier.

Sprinkle chopped pistachios on top of donuts to make it peeerty!