Whisk together the soy milk and vinegar. Set aside.
In a mixing bowl, whisk the flour, sugar, baking powder, and salt.
Using a fork or pastry cutter, cut in the butter cubes.
Gently stir in the milk mixture until just combined (dough will be sticky).
Place your dough on top of a lightly floured surface. Gently flip it around to cover in flour.
Pat the dough out to be ~1/2 inch thick. Use a biscuit cutter or top of a cup to make the rounded pieces of dough. You can reshape the dough scraps to make more biscuits.
Place each piece of dough on a lined baking sheet so that it is touching other pieces (this will help them rise).
Place your baking sheet into the fridge for 15-30 minutes to firm up before baking.
Preheat the oven to 425°F.
Once your dough pieces have chilled, brush each with soy milk and top with a sprinkle of sugar.
Bake for ~15 minutes, until the bottoms are golden brown and tops are crackly.
Enjoy by slicing the biscuits in half and filling with strawberries and whipped cream!