Preheat the oven to 400°F / 204°C.
In a large bowl, mix until combined the baking powder, salt, sugar, baking soda and flour. Add small pieces of vegan butter and mix them until they are covered in flour. Add the vegan yogurt, Greek yogurt and cashew milk and combine with your hands until the mix is together and looks shaggy. Be careful to not overmix.
Dust the counter with flour and bring down the dough. Form a 1″ thick square with your hands, pressing along the dough. Then, cut the dough into four squares with a knife or pizza cutter. Make a tower with the four squares and press them down with your hands. Roll the dough to a 1″ thick rectangle. Trim the borders to have clean edges. Cut the rectangle into 8 squares. Place the biscuits on an oven tray covered with parchment and freeze them for 20 minutes.
Bake the biscuits for 20 - 25 minutes, until they are golden brown.
Meanwhile, make the gravy. Heat a large skillet over medium heat and melt the butter. Add the minced vegan sausage and the onions, cook them until they start to brown. Then, add the flour, mix everything together and cook for about one minute. Finally, add the cashew milk, nutmeg, garlic powder and pepper. Mix and bring to a boil, cook until the gravy has thickened. Season with salt.
Open the biscuits in half, fill with gravy and top with fresh parsley. Enjoy.