Whisk milk and vinegar in a large mixing bowl and allow it to sit for about 5 minutes. Meanwhile, sift together the sugar, flour, baking powder, spices, and salt in a separate bowl. Now add the coconut cream, mashed sweet potato, and vanilla to the milk and stir until combined. Add dry ingredients and mix until just smooth. (If the batter seems too thick or too thin you can adjust it with a small amount of milk or flour).
If you have trouble finding coconut cream at your local grocery store it's completely fine to use full-fat coconut milk and scrape the cream off of the top. Just be sure that it's cold enough to separate.