Preheat the oven to 350 degrees Fahrenheit and grease and line a 9 inch cake pan with parchment paper. Set aside.

Measure out 1 cup of milk. Add in 1 tablespoon white vinegar. Mix with a spoon and let sit for 5-10 min. Stir again.The milk should appear chunky and that’s normal. This is our homemade buttermilk. Set aside.

Whisk the 1.5 cups gluten free flour, 1.5 cups of granulated sugar, ¾ cup cocoa powder, 1.5 teaspoons baking soda, ¾ teaspoon baking powder and ¾ teaspoon kosher salt in a large bowl until combined.

In a small bowl, using a spoon, mix together the 4 heaping tablespoons of cornstarch and the 6 tablespoons of water until thin and watery. It will be thick and tacky at first.

Make a well in the center of the dry ingredients. Add the cornstarch water, homemade buttermilk, 1 cup warm water, 4 tablespoons vegetable oil and 1 teaspoon pure vanilla extract. Whisk until smooth. If it starts to get too thick, use a spatula to mix the rest.

Using a spatula, scoop the batter into a greased and parchment lined 9 inch cake pan and smooth the top with a butter knife.

Bake the cake in the center rack at 350 degrees Fahrenheit for 60 minutes until the top is risen and slightly springy when carefully touched. Or when a toothpick inserted comes out clean.

Let the cake cool in the pan for 15 mins before trying to remove. Then remove from pan and place on a wire cooling rack.

Carefully use a cake knife to cut a thin layer off the top of the cake to make it flat and level. Break or cut the excess into tiny crumbs and set aside.

Place the 6 ounces chocolate chips in a heat safe bowl. Set aside.Pour the ½ cup heavy cream in a saucepan over medium heat, whisking constantly. Once it begins to simmer around the edges, immediately pour the cream over the chocolate chips.

Cover with plastic and let site one minute. Then remove plastic and whisk until smooth.

Immediately spoon all the liquid ganache on top of the cake.Using an icing spatula, push the ganache around the edges of the cake so it drips down the sides.

Sprinkle the chocolate crumbs around the top rim of the cake.