Preheat the oven to 350 degrees F. Grease a 9 inch cake pan with some coconut oil, then dust the pan with a little cocoa powder.
Place the coconut oil in a mixing bowl and microwave for about 30 seconds until melted.
Add the cocoa powder and sugar, and mix together.
Add the flour, baking soda, salt, water, and vinegar. Mix well until combined and smooth. You can use a mixer for this, or just do it by hand.
Pour the batter into the prepared pan and bake for about 26-28 minutes at 350 degrees F. When the top of the cake springs back when pressed with your finger, the cake is done. You can also stick a toothpick in the middle to see if it comes out clean.
Allow the cake to cool for about 30 minutes before removing from the pan. You can turn it out over a plate to let it cool fully before frosting it.
Make the frosting:
Melt the coconut oil in the microwave and set it aside to cool for a few minutes.
Sift the powdered sugar and cocoa powder into a mixing bowl.
Add the coconut oil and the water and mix on medium speed until the frosting is smooth and creamy. If the frosting is too thick, add a little more water.
Frost the cake and enjoy!
Notes
Nutrition facts are for ⅛ of the cake with frosting.This cake does not need to be refrigerated.If you want to use a different oil, you can! Canola oil or vegetable oil should work. Any neutral tasting oil that you like to bake with should be just fine.