1 Envelope active dry yeast
3/4 Cup plus 1 teaspoon sugar
1/4 Cup warm water (110 degrees)
6 Large eggs, at room temperature
4 Tablespoons (1/2 stick) unsalted butter, melted
1 1/2 Cup half-and-half, at room temperature
1/4 Teaspoon salt
8 1/2 Cups all-purpose flour
Vegetable oil for deep frying
Sugar for sprinkling
In a small mixing bowl, combine the yeast, 1 teaspoon of the sugar, and the water. Stir to dissolve the sugar and set aside. If the yeast doesn’t foam after a few minutes, you need to buy new yeast and start again.
In an electric mixer, beat the eggs and the remaining 3/4 cup sugar until thick and pale yellow in color, about 6 minutes. Change the mixer attachment to a dough hook. With the machine on low speed, slowly add the yeast mixture, melted butter, milk, half-and-half, and salt. Add flour, 1 cup at a time, and mix until a soft ball forms that leaves the sides of the bowl and climbs up the dough hook. Remove the dough and turn into a lightly oiled bowl, turning it to oil all sides. Cover the bowl with plastic wrap and set the bowl in a warm, draft-free place until it doubles in size, about 1 1/2 hours.
Turn the dough out onto a floured work surface and dust it with flour. Roll out the dough into a rectangle about 12 by 17 inches and 1/2 inch thick. Cover the dough with a lightly oiled piece of plastic wrap. Put the dough in a warm, draft free place and let rise until doubled in size, about 1 hour.
Heat 6 inches of oil in a deep, heavy pot or and electric fryer to 360 degrees.
With a sharp knife, cut the dough into 2-inch squares. Flour your hands, then pat the squares down a little to lightly flatten them. Fry the squares, 2 to 3 at a time, until golden brown, 3 to 4 minutes. turning them to brown evenly. Drain on paper towels. Sprinkle the doughnuts with sugar and serve warm.