In a microwave safe bowl, place soy milk and vegan margarine, and microwave on high for about 10 seconds, or just long enough to melt most of the margarine.
Whisk together soy milk, melted vegan margarine, lukewarm water, and active dry yeast. Allow the mixture to sit for just a minute or two, just to make sure that your yeast gets ever so slightly foamy.
Add vanilla, salt, cornstarch, and sugar to your wet ingredients and whisk together.
Kneed flour and wet ingredients together for a few minutes until a sticky dough forms. You can use a mixer or your hands (my preference). Depending on your flour brand, you may need to add a teaspoon of water or flour, just to make sure your dough is slightly moist/sticky and not too dry. I know my dough is just right when it mostly sticks to itself, but still clings to my fingers just a tiny bit too.
Place dough in a clean bowl, covered with plastic wrap or a kitchen towel, and put in a warm dry place to rise for 60 minutes.
Meanwhile, you can start putting your filling together. Melt your vegan margarine in a microwave, then mix it with your applesauce in a small bowl or cup. In a separate small bowl, mix together your brown sugar, cinnamon, and salt.
Roll dough out on to a lightly floured surface and roll into a 12 inch by 22 inch rectangle.
Brush the rectangle with your margarine/applesauce mixture--making sure all the edges and corners get coverage as well. Now, sprinkle your brown sugar/cinnamon mixture over the rectangle evenly.
Roll the rectangle up lengthwise (meaning, make a 22 inch long roll). Cut your roll into 12 equal rolls, and place in an oiled 9 x 13 inch baking dish. (Mine was glass.)
Place that baking dish in a warm dry place (I like to turn my oven on for just a minute, then turn it off, and put my rolls in there), and let your rolls rise for about 30 to 45 minutes.
Preheat your oven to 325 degrees Fahrenheit. (Make sure it's empty!) Then, bake your cinnamon rolls for about 30-35 minutes--or just until the tops are golden brown, and a fork comes out clean. Nobody likes doughy cinnamon rolls. ;)
I like to douse mine in plain 'ole coconut milk or cream without any extra sweetener or anything. Enjoy!