Preheat the oven to 400 degrees Fahrenheit and line a baking sheet with parchment paper.
In a liquid measuring cup add 1/2 tsp lemon juice to the 1/2 cup almond milk. Place back in the fridge.
In a large bowl whisk together the 1:1 gluten free flour, salt, baking soda, and brown sugar.
Cut the cold vegan butter (Earth Balance) into little squares and add to the dry ingredients. Using a fork or pastry blender mash the butter and dry ingredients together until the dough is clumpy with little balls the size of blueberries or peas.
Add 1 cup of cold sweet potato puree and 1/4c of the almond milk/lemon juice mixture, mix slowly and add the remaining milk mixture. The dough should form nicely into a ball.
Transfer the dough to a lightly floured surface (pastry mat or a cutting board lined with parchment paper). Cover dough with a light dusting of flour and parchment paper and roll out to 1/2" thickness. Use a biscuit cutter to cut out circular biscuits at whatever size you would like and place on a parchment paper lined baking sheet.
Bake for 15-18 minutes, or until biscuits look flaky and slightly browned around the edges (check more frequently if you use a mini biscuit cutter). Store in an airtight container for up to 4 days.