Preheat the oven to 350°F (175°C) and spray a donut pan with nonstick cooking spray; set aside.
In a large bowl, whisk together the cake mix, egg, vegetable oil (or applesauce), and 1 cup chocolate almond milk until just smooth and combined.
Transfer the batter to a large plastic bag or piping bag and snip off one corner with scissors.
Pipe the batter into the prepared donut pan, filling each well about half full. Do not overfill.
Bake for 10 to 12 minutes, or until a toothpick inserted into a donut comes out clean.
Let the donuts cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely before glazing.
For the glaze, sift the powdered sugar and unsweetened cocoa powder into a medium bowl.
Slowly add 2 tablespoons chocolate almond milk and 2 teaspoons vanilla extract to the dry ingredients, whisking until smooth.
If the glaze is too thick, add more almond milk a drop or two at a time; if too thin, add powdered sugar 1 teaspoon at a time until desired consistency is reached.
Dip the cooled donuts into the chocolate glaze, top with sprinkles or desired toppings, and serve immediately.