Just wait until you taste this cake, it's so easy to make the complete cake is mixed in one just bowl, this cake so rich and moist it's a chocolate-lover's dream! I use the mocha frosting for many other cakes also, it's to die for! :)
For the cake; combine the flour, both sugars, baking powder, baking soda and salt in a large mixing bowl; add in the mayonnaise and oil, beat on medium speed of an electric mixer until thoroughly combined.
Carefully and slowly add in the hot brewed coffee and vanilla; beat until blended (about 1 minute).
Add in the mini chocolate chips; mix to combine.
Pour the batter into prepared baking dish.
Bake for about 30 minutes, or until cake tests done.
Cool completely on a wire rack.
For the mocha frosting; in a large bowl combine the boiling water with the coffee granules; stir until the granules completely dissolve.
Add in the marshmallow cream; beat on low speed until smooth.
Using a spatula fold in the Cool Whip topping.
Spread over the top of the completely cooled cake.