Heat the soy milk in the microwave for about a minute until it's as warm as bath water. Too hot and it could kill the yeast. You could also warm it in a small pot.
Pour the warmed milk into a large bowl, or the bowl of a stand mixer. Add the instant yeast and sugar, give it a little stir and let sit for 3-4 minutes, until it's a bit frothy.
To the bowl with the yeast/milk/sugar mixture, add the applesauce, softened vegan butter, vanilla, salt and 2 cups of flour. Mix on low speed with a dough hook (or by hand with a spoon) for a few minutes, then add the rest of the flour and mix, until a soft dough starts to form.
If using a stand mixer, beat with the dough hook for 2-3 minutes. If you are mixing the dough by hand, mix it as well as you can with a spoon, then transfer to a lightly floured surface and knead for about 5 minutes until you have a soft, sturdy ball of dough. It may be slightly sticky, but if it's very sticky, add flour, a little at a time, until it's easier to handle.
Lightly grease a large bowl, then place the dough inside the bowl. Cover with a tea towel, and allow to rise in a warm place for 30 minutes. I preheat my oven to 170℉, then turn it off, place the bowl inside and leave the oven door cracked.
After 30 minutes, punch the dough down gently, and place on a floured surface. Roll to about 1/2 inch thick and use a donut cutter (or biscuit cutter) to cut the donuts into round circles. You will get around 16.
Line a large baking sheet with parchment paper, and place the cut donuts on it. Cover with the towel for about 15 minutes while you heat the oil.
Heat 2-3 inches of oil in a large pan or pot until it reaches 375℉. Use a food thermometer to ensure the right temperature.
Add a few donuts at a time to the oil and cook for about 1-2 minutes on each side, until golden brown, being careful not to let them get too dark and burnt. If the oil is hot, this won't take long. Beware of splattering oil!
Place the cooked donuts on a cooling rack with a pan or parchment paper underneath to catch any oil drippings. Repeat until all donuts are fried.
Make the chocolate glaze: Place chocolate chips, vegan butter, corn syrup and water in a small bowl and microwave in 30 second increments, stirring after each time, until completely melted and smooth.
Cut a deep slit in each donut, then use a piping bag with large tip and pipe pastry cream into each one. Dip the tops of the donuts in the glaze, then place back on the cooling rack. Enjoy!