Preheat oven to 350°F. Line an 8 inch x 8 inch baking pan with parchment paper.
Add flour, cocoa powder, sugar, baking powder into a large mixing bowl. Whisk together until evenly combined.
Add in oil, milk and water. Whisk until batter is smooth.
Pour batter into prepared baking pan. Bake for about 35 minutes or until toothpick inserted comes out clean and top of cake bounces back when you apply light pressure. Let cake cool completely before frosting and cutting.
To make chocolate ganache: Add chopped chocolate to a medium bowl. Bring heavy cream to a simmer on the stove. Pour heated heavy cream over chopped chocolate and immediately start to mix until the chocolate is completely melted and smooth. Let chocolate ganache cool at room temperature or in the fridge until it becomes firm enough for frosting the cake.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.