1-In a bowl: sift together 2 1/4 cups bleached cake flour, 1 1/2 teaspoons baking powder, 1 teaspoon fine sea salt, and 1/2 teaspoon ground nutmeg.

2-In a stand mixer bowl fitted with a paddle attachment, beat 2 tablespoons (29 grams) butter and 1/2 cup (100 grams) sugar until sandy. Add 2 large egg yolks and mix until light and thick.

3-Add the dry ingredients in three additions, alternating with 1/2 cup (113 grams) sour cream, ending with the flour. Mix on low speed for 30 seconds until the dough is smooth but slightly sticky.

4-Cover the dough with plastic wrap and chill for 1 hour or until firm.

5-Roll out the dough on a floured surface to about 1/2 inch thickness. Cut out doughnuts and holes using cutters, and keep the dough cold if it becomes too loose or sticky.

6-Heat canola oil to a depth of 2 inches in a heavy-bottomed pot to 325 degrees Fahrenheit. Fry the doughnuts a few at a time for about 2 minutes per side until golden, then drain on paper bags.

7-For the glaze, whisk together 3 1/2 cups (350 grams) sifted powdered sugar, 1 1/2 teaspoons corn syrup, 1/4 teaspoon fine sea salt, 1/2 teaspoon vanilla extract, and 1/3 cup hot water until smooth. Dip each doughnut in the glaze, place on a wire rack, and let set for 20 minutes.