Begin by adding your warmed almond milk and yeast to a large mixing bowl. Let sit for 3-5 minutes to make sure the yeast is activated. You will be able to tell if it's bubbling. If using instant yeast, you can skip this step and add the yeast directly to the mix with the flour and salt.
Next, add the sweet potato purée, sugar, melted vegan butter, and vanilla to the large mixing bowl and whisk together to combine.
Once mixed, gradually begin adding in your flour about ½-1 cup at a time. Also, add in the 1 tsp of salt at this time.
Once all the flour has been added in, knead the dough. If using a standing mixer, switch the attachment to the bread hook and knead for 5-10 minutes until elastic. If you are kneading by hand, knead on a lightly floured surface for 10-15 minutes or until the dough is elastic and significantly less sticky. (Since the dough has sweet potato in it, it will be stickier than normal bun dough, but should firm up a lot during kneading). The dough is done being kneaded once it can be stretched without easily tearing, is smooth, and tacky but not sticky.
Once the bread is ready, add it to a well oiled bowl for the first rise. I prefer to coat my bowl in olive oil, but any oil works here. The dough will be sticky so you may want to lightly oil your hands before grabbing the dough.
Then, cover the bowl with plastic wrap or a towel, place in a warm place, and let rise 1 hour or until doubled in size. I like to test my dough by "poking" it with a finger. If it doesn't bounce back and stays indented, it is ready. It is also important to not “overproof” the dough as it can turn sour from the yeast turning the sugar into alcohol, so do not let the dough sit too long.