In a small saucepan, heat the plant-based milk and vegan butter until warm (not boiling). Remove from heat and stir in the sugar. Let it cool to about 100°F.
Pour the warm mixture into a mixing bowl and sprinkle the yeast on top. Let it sit for about 5-10 minutes until foamy.
Add 2½ cups of flour and salt to the yeast mixture. Mix until a sticky dough forms. Gradually add the remaining flour as needed, kneading until the dough is smooth and elastic (about 5 minutes).
Place the dough in a lightly oiled bowl, cover with a cloth, and let it rise in a warm place for about 1 hour, or until it doubles in size.