Vegan Chocolate-Covered Digestive Biscuits (Vegan McVities)

Name: Vegan Chocolate-Covered Digestive Biscuits (Vegan McVities)
Prep time: 25 min
Cook time: 25 min
Total time: 50 min
Yield: 16
Ingredients: 4 1/2 ounces all-purpose flour (about 1 cup, spooned; 125g); 2 ounces whole wheat flour (about 1/3 cup; 55g), plus more for dusting; 2 1/4 ounces quick-toasted sugar (about 1/3 cup; 60g); 1/2 teaspoon cream of tartar; 1/4 teaspoon baking powder; 1/4 teaspoon baking soda; 1/8 teaspoon (1/2g) Diamond Crystal kosher salt; for table salt, use about half as much by volume or use the same weight; 4 ounces refined coconut oil (about 2/3 cup; 113g), solid and cool; 3/4 ounce water (about 5 1/4 teaspoons; 20g); 9 ounces roughly chopped vegan chocolate (about 1 1/2 cups; 285g) (see note)