Preheat the oven to 350˚F. Line muffin pan with paper liners.
In a medium bowl, combine the flour, cocoa, baking powder and salt.
In a separate bowl, with an electric mixer, mix together the maple syrup, milk, oil and vanilla.
Slowly add the wet ingredients to the dry ingredients, mixing until fully incorporated
Pour the batter into the lined muffin pans, and bake for around 12 minutes, or until a toothpick inserted comes out clean. Allow to cool.
Buttercream: Cream together all of the buttercream ingredients until smooth. Pipe over cooled cupcakes.