To make the cake, preheat the oven to 350°F (175°C). Spray two 9-inch round cake pans, or two 9-inch heart-shaped cake pans with cooking spray.
Whisk together flour, sugar, cocoa and salt. Set aside.
In a large mixing bowl, beat the eggs, vegetable oil, buttermilk, red food coloring, and vanilla extract until well combined. Add the flour mixture and mix until smooth, about a minute.
In a small dish, mix together baking soda and vinegar. While the soda/vinegar mixture is bubbling, add it to the batter and mix well.
Divide the batter equally between the 2 cake pans. Bake for about 30-35 minutes, or until the inserted toothpick comes out clean. Cool the cakes in the pan for 5 minutes, and then invert them onto a wire rack to cool completely.
To make the filling, beat butter and cream cheese on medium high speed until fluffy, about a minute. Add powdered sugar, heavy cream and vanilla extract. Beat on low speed for a minute. Then increase the speed to medium high and continue to beat until smooth and fluffy, about 3 minutes.
To assemble the cake, cut each cake layer horizontally. Spread about 1/5 of the filling between each layer and stack the layers on top of each other. Evenly spread the remaining 1/5 of the frosting on the sides of the cake. Refrigerate the cake to chill while prepare the ganache.
To make the ganache, in a small saucepan, bring heavy cream to a simmer. Do not boil. Pour hot cream over chocolate chips, and let it sit for good 2 minutes. Then mix well until smooth for couple minutes.
For the smooth coverage, pour the ganache over the cake while the ganache is still runny. The longer it cool, the thicker it gets.
Store the cake covered in the fridge for up to 5 days. Bring it to room temperature, before serving.
For step-by-step photos and additional notes, read the post above.