Warm the milk in a microwave-safe measuring cup for about 20 seconds to make it warm but not hot.

Pour the warmed milk into the bowl of your stand mixer fitted with a dough hook or a large mixing bowl.

Stir in the sugar and then sprinkle the yeast over the top. Let it sit for 5 minutes until it becomes foamy.

Mix in the sourdough discard, eggs, melted butter, cocoa powder, instant espresso (if using), and salt.

Gradually add the flour in three batches, mixing until combined.

If using a stand mixer, knead on low speed for 4-5 minutes until smooth. If kneading by hand, do so until the dough is soft and slightly wet but not sticky.

Place the dough in a lightly oiled bowl, cover it, and refrigerate for 1-2 hours, or overnight for 8-10 hours.

Once cold, roll the dough on a floured surface to a thickness of 1/2 inch. Cut out donuts using a 3-inch cutter.

Set the cut donuts on lightly floured parchment-paper-lined baking sheets, allowing room to expand. Spray them with nonstick spray and cover with plastic wrap. Let them rise at room temperature for 45 minutes until puffy.

Near the end of the rising time, heat oil in a pot to 350°F.

Prepare a second baking sheet with paper towels to drain the cooked donuts.

For the glaze, sift powdered sugar into a bowl. Lightly warm heavy cream in the microwave for 10 seconds, then stir in vanilla extract and salt.

Carefully add donuts to the hot oil, frying for about one minute on each side. Remove with a slotted spoon and drain on paper towels.

Dip the warm donuts into the glaze, coating them fully, and then place them on the parchment-lined sheet to set.

Repeat until all donuts are fried and glazed. Enjoy your delightful treats!