For the cupcakes: Preheat the oven to 350°F and line a standard 12-cup muffin tin with unbleached paper liners. In a large bowl, whisk together the light spelt flour, baking powder, baking soda, and sea salt.
In a medium bowl, whisk together the maple syrup, non-dairy milk, coconut oil or butter, and vanilla extract.
Pour the wet ingredients over top of the dry ingredients and whisk to combine. Quickly whisk in the apple cider vinegar.
Pour 1/3 cup batter into each cup. Bake for 22-27 minutes, or until golden on top and a toothpick inserted in the center cupcake comes out clean.
Allow the cupcakes to cool in the pan for 20 minutes before removing them to finish cooling on a wire rack.
For the frosting, place the avocado, maple syrup, cocoa, cashew butter, vanilla, sea salt, and non-dairy milk in the bowl of a food processor fitted with the 'S' blade. Blend until smooth.
Once the cupcakes have cooled completely, frost them and serve immediately.
Keep any leftovers in the fridge due to the perishable nature of the avocado frosting.