Preheat oven to 450 degrees F.
Add lemon juice to almond milk to make vegan buttermilk. Set aside.
In a large mixing bowl, whisk together dry ingredients. Add cold butter and use fingers to combine the butter and dry ingredients. It should look like a crumbly sand when it is ready. You don’t want the butter to get too warm in this stage, so work quickly.
Make a well in the dry ingredients using your finger. Pour in the vegan buttermilk mixture slowly, about 1/4 cup at a time, while gently stirring. Stir until just slightly combined. It will be very sticky.
Put dough on a floured surface such as a cutting board. Dust the top of the dough with additional flour. Turn the dough over on itself 5 times – barely kneading. This is a very gentle step. It is important to not overwork the dough.
Using floured fingers, press the dough into a 1-inch thick circle, handling as little as possible. You might need to add additional flour if the dough is too sticky.
Use a small dough cutter or a circular object with sharp edges (I used a small mason jar) and press straight down through the dough, then slightly twist. When you lift up, you will have the familiar biscuit shape. Place biscuits on a baking sheet in two rows, making sure they barely touch. Repeat until all dough is used. If needed, gently reform the dough and cut additional biscuits.
Brush the biscuit tops with melted non-dairy butter. Press a small divot in the center of the biscuit using two fingers. This helps to prevent a dome from forming.
Bake for 10-15 minutes, until fluffy and slightly golden brown. Serve immediately.