Cake donuts are heavier and denser than regular bready donuts so don’t expect the same product as your favorite Krispy Kreme.

PREPARATION

1. Make the doughnuts: Heat 4 cups/960 milliliters of oil in a large heavy bottomed pot (preferably wider than taller) over medium heat to 375 degrees.
2. In a large bowl, whisk together flour, sugar, baking powder, kosher salt and nutmeg.
3. In a medium bowl, whisk together sour cream, buttermilk, egg, egg yolk and 3 tablespoons oil. Add the wet ingredients to the dry, using a wooden spoon to gently mix just until a dough comes together (you want to keep it rather shaggy; do not overwork the dough).
4. Transfer dough to a floured work surface and knead 4 or 5 times, just until no wet or dry spots remain, sprinkling in additional flour as necessary (dough should feel supple but not wet).
5. Pat dough (no need to use a rolling pin here) to a thickness of about ¾-inch. Using a 3 1/8- to 3 1/4-inch ring cutter, punch out as many circles as you can. Using a 1 ¼-inch ring cutter, punch out the center of each circle. (Dipping the rings in flour before each cut helps to avoid sticking.) The scraps of dough can be gathered and gently pressed again two more times to cut the rest of the doughnuts, continuing to flour your work surface as needed.
6. Working in batches, gently lower doughnuts into the oil (no more than 4 or 5 at a time). Fry on one side until deeply golden brown, about 2 minutes. Flip with tongs or a skimmer and continue to fry until golden brown and cooked through, another 2 minutes.
7. Drain doughnuts on a wire rack lined with paper towels and proceed with remaining doughnuts, making sure the oil returns to temperature between batches.
8. To make the vanilla glaze: In a medium bowl, whisk together powdered sugar, buttermilk, vanilla extract and salt until no lumps remain. Add additional buttermilk if necessary, 1 tablespoon at a time, to thin the glaze.
9. Remove paper towel from wire rack. Dip each doughnut into the glaze on one side, letting excess drip back into the bowl, and return it to the wire rack. Sprinkle immediately with sprinkles, chopped nuts or toasted coconut.
10. To make the chocolate glaze: In a medium bowl, whisk together powdered sugar, cocoa powder, buttermilk and salt until no lumps remain. Add additional buttermilk if necessary, 1 tablespoon at a time, to thin the glaze.
11. Remove paper towel from wire rack. Dip each doughnut into the glaze on one side, letting excess drip back into the bowl, and return it to the wire rack. Sprinkle immediately with sprinkles, flaky sea salt, chopped nuts or toasted coconut.