Sweet Potato Chocolate Cake

Name: Sweet Potato Chocolate Cake
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American
Ingredients: 130 g (4.6 oz) sweet potato purée; 150 g (5.3 oz) soy milk; 40 g (1.4 oz) neutral-tasting oil; 70 g (2.5 oz) sugar; 25 g (0.9 oz) cocoa powder; 50 g (1.8 oz) flour; 1 tsp baking powder; 1/2 tsp baking soda; 50 g (1.8 oz) sweet potato purée; 1 - 2 tbsp cocoa powder; vanilla extract or ground vanilla; maple syrup to taste