In a heat-proof microwave bowl, melt together the chocolate and coconut oil in 30 second increments, stirring each increment until melted. Set aside to cool slightly.
Sift together the all-purpose flour, baking powder, baking soda, cocoa powder and salt. Add the sugar and whisk well until everything is evenly distributed,.
Mix together the non-dairy milk, warm water/coffee, lemon juice, and (extract or espresso powder, optional) add them to the dry ingredients.
Pour in the melted chocolate/coconut oil mixture, and whisk well for a smooth cake batter.
Transfer the cake batter to the lined cake pan, smooth out the top, and bake at 350ºF or about 1 hour or until an inserted toothpick/skewer comes out clean.
Allow the cake to cool in the baking pan for about 10 minutes, then remove from the baking pan and transfer to a wire cooling rack to cool completely.