In a large bowl, sift together the flour and baking powder. Whisk in the salt. Set aside.

Line a large mixing bowl with plastic wrap and then spray the surface of the plastic wrap. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat together the sugar, butter (or margarine) and egg yolks on high speed until the mixture lightens, about two minutes. Add the sour cream, then mix on medium until the mixture is smooth.

With the mixer on low, gradually add the dry ingredients to the bowl, a half cup at a time, until all the flour is incorporated. Transfer the dough to the plastic-wrap-lined-bowl and cover. Refrigerate for at least 60 minutes or up to one week.

Line a sheet pan with Gefen Parchment Paper and spray the paper with baking spray and set aside.

Lightly dust a work surface with flour. Turn the dough out onto your floured work surface and dust lightly with more flour.

Roll out the dough to half an inch thick. Use a doughnut cutter to cut the donuts and holes. Place the donuts and donut holes on the lined sheet pan.  Cover sheet pan with plastic wrap and chill in the refrigerator for 30 minutes or overnight.

Heat three inches of oil in a Dutch oven to 350 degrees Fahrenheit.  Gently place three donuts in the pot, keeping the remaining donuts in the fridge. The beautiful crackly texture is achieved by frying cold dough. Once they rise to the surface, cook for a minute and a half and then flip them with a slotted spoon. Fry until the color is golden brown. Transfer to a wire rack set over a sheet pan or paper towels.

Donut holes will cook faster, about a minute on each side.

In a medium bowl whisk together the milk, confectioners’ sugar, and salt. Dip warm donuts into glaze.