Preheat oven to 425F. Line a baking sheet with parchement paper.
Add the flour, baking powder and salt to a large bowl. Whisk until combined. Set aside.
Combine the milk and apple cider vinegar to make your vegan buttermilk. Set aside.
Add the cold vegan butter to the dry ingredients and cut into the flour using a pastry cutter, a fork or by using the stand mixer until you get a coarse crumb.
Make a well into the center of the bowl. Pour the prepared buttermilk into the well, then mix everything together. Don’t overwork the dough! It should look crumbly. Add the scallions and nutritional yeast and mix until just combined.
Place the dough onto a lightly floured surface. Lightly press the dough to form a rectangle using your hands or a rolling pin. Fold the dough, one side to the center, then the other. Flatten, then repeat this step 2 more times. This helps you get flaky biscuits.
Roll out the dough using a rolling pin until about ½ inch thick. Cut into 2.5 or 3-inch circles. Make sure not to twist the cutter as this will seal the sides and prevent the biscuits from rising. Shape the dough again as needed until all the dough is used. You should get about 12 biscuits.
Place the biscuits on the prepared baking sheet. Make sure they’re touching as this helps them rise higher.
Brush the top of the biscuits with almond milk if desired.
Bake for 15 minutes or until crisp on the outside and soft on the inside.