Prepare Martha Stewart's vegan chocolate ganache according to the recipe linked above. Set aside to cool and thicken.
Whisk flour, cocoa powder, baking soda, and salt together in a large mixing bowl. Set aside.
In a separate mixing bowl, combine maple syrup, milk, oil, egg, and vanilla extract, and whisk until combined.
Gradually add wet ingredients to dry ingredients and mix well until all dry ingredients are fully incorporated.
Add hot water to the batter and whisk until combined. The batter will be very thin.
Line one medium-sized muffin tin with cupcake liners, then fill each liner approximately halfway until all batter is used (should yield about 12 cupcakes).
Bake at 300°F for 20 minutes or until a toothpick comes out clean.
Once cupcakes and ganache are cooled, pipe a thin layer of ganache on top of the cupcakes. You might need to place the ganache in the refrigerator for 10-15 minutes to create a pipeable consistency.