1. In large bowl, whisk together flour, coconut sugar, cocoa powder, baking soda and salt. In a smaller bowl, using a hand blender, mix together oil, avocado, vanilla, vinegar and water until smooth.
2. Pour wet mixture into dry ingredients and whisk well (mixture will be thick).
3. Pour into greased and floured 9 x 11 inch oblong cake pan. If batter it is too thick to get a smooth surface, dip a knife into water and smooth top of batter.
4. Bake in 350°F oven 30-35 minutes or until toothpick inserted in centre comes out clean. Let cool completely in pan.
Mix all frosting ingredients together in a small saucepan over medium low heat. Stir until melted and smooth and remove from heat.
- Let the pot cool for about 15 minutes and place in the fridge for about 10-20 minutes, stirring every 5 minutes, until it's firm enough to spread on the cake.
- Carefully spread frosting over cake.