Add milk, pumpkin puree, and sugar to the bowl of your stand mixer. Add bread flour, wheat flour, and vital wheat gluten on top. Add salt to one side of the bowl and instant yeast to the other side.
Attach a dough hook to your stand mixer. Turn it on at low speed to combine the ingredients, then gradually increase speed to medium as the dough comes together. Knead on medium for about 5 minutes. The dough should come together into a ball and loose most of its stickiness. Turn off the stand mixer, cover with a towel, and let the dough rest for 10 minutes.
Turn the mixer back on at low speed and gradually add in the butter pieces. Increase the speed to medium as the butter gets incorporated into the dough. Continue kneading on medium speed (4-5) for about 10-15 minutes. You can stop to scrape down the dough if needed.
Make Dough (By Hand)
Clean a work surface or set out a large pastry mat and lightly dust with bread flour.
Whisk together flours, vital wheat gluten, sugar, salt, and yeast. Pour in soy milk and pumpkin puree and use a wooden spoon to mix until a dough starts to form. Gather the dough into a loose ball and transfer to your work surface.
Knead the dough for 5-10 minutes until a tight dough forms and it looses most of its stickiness. If the dough is too sticky, you can sprinkle some flour on top but try not to add too much flour or your bread will turn out dense. Dough will stick to your hands during kneading at first but just keep kneading! Cover and let the dough rest for 10 minutes.
Stretch the dough out into a long rectangle and add the butter pieces on top. Roll up the dough and continue kneading. It will be very messy and greasy at first but keep going! After a couple minutes the dough will become smooth and easier to work with.
Continue kneading for another 10-15 minutes.
Windowpane Test
Use the windowpane test to check if the dough is sufficiently kneaded. Tear off a small piece of dough and gently stretch it into a square, pulling at the four corners. You should be able to stretch the dough out into a very thin membrane that light can pass through. If the dough tears easily, it needs to be kneaded longer.
First Rise
Shape the dough into a ball and place in a large bowl (you can use the bowl of your stand mixer). Cover with a towel or plastic wrap and set on the counter to rise for 1-2 hours until doubled in size.
To test if the dough is ready, use your finger to poke a hole in the center of the dough. If the hole doesn't close up, it's ready.
Second Rise
Grease a 9"x9" baking pan with vegan butter.
Punch down the dough and transfer to your work surface. Shape into a ball, then use a dough scraper to divide into 9 pieces.
Shape each piece into a ball and place in the baking pan, leaving some space between each ball.
Cover the dough and set aside to rise for about 40 minutes or until doubled in size.
When the dough has risen a little over halfway (after about 20 minutes), preheat oven to 350°F/180°C.
Bake
Uncover dough and lightly brush the tops with soy milk.
Bake for about 25 minutes until golden brown. The edges should be cooked and the rolls will sound hollow if you tap them.
Place the pan on a wire rack.
Whisk together soy milk and maple syrup. While the rolls are still warm, brush the tops with the glaze (this will make them look shiny and keep the tops soft).
Rolls are best served warm after cooling in the pan for a few minutes.