Preheat oven to 350℉.

Mix all dry ingredients in a bowl and set aside.

In a larger bowl, mix water, vanilla and mayo until smooth and slowly stir in dry ingredients with a whisk. To keep cake light and airy, do not over mix.

Pour batter into lightly greased 9x13 baking dish.

Bake for 40-50mins (or until toothpick comes out almost clean) and let the cake cool completely.

In a heat safe bowl, add all of the chocolate chips and set aside.

Heat up the heavy cream slowly in a small pan on the stove until it's simmering (DO NOT MICROWAVE).

Pour the cream over the chocolate chips and let it melt to form the ganache, stirring with a metal spoon or spatula until it cooks down (this could take up to 30 mins. You can speed this process up by putting the mixture in the fridge and stirring occasionally).

Once cooled, slowly and evenly pour the ganache over the cake and let it sit for 30 mins in the fridge. Make sure to cover the cake to allow it to finish setting up.