In a large bowl, whisk mashed avocado and melt chocolate. Whisk in sugar until combined, then add in eggs and vanilla extract, mixing well. Add in flour, cocoa, baking powder and salt, mixing with a large spoon until JUST combined – do not over mix. Stir in avocado oil until it’s well distributed and batter is somewhat smooth. Fold in chopped chocolate, then spread batter in pan. Bake for 28-32 minutes, or until middle is set. Remove and let cool completely, then frost and top with grated chocolate if desired.