Preheat oven to 350°F. Grease and flour an 8-inch round cake pan.
In a medium bowl, combine the flour, cocoa powder, baking soda, baking powder, and salt. Whisk together until combined.
In a large bowl, cream the butter and sugar together until light and fluffy.
Add the eggs one at a time, mixing until incorporated.
Add the vanilla extract, mix until combined.
Add the dry ingredients in thirds, alternating with the buttermilk and mixing until just combined. Do not overmix.
Pour the batter into the prepared pan, and bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and let cool completely.
Once the cake is cool, cut it in half and spread the softened ice cream between the two layers.
Place the cake in the freezer for at least 2 hours.
In a small saucepan, heat the heavy cream until it just begins to boil. Remove from heat and add the chocolate chips, stirring until melted and smooth.
Pour the chocolate ganache over the cake and spread to cover. Return to the freezer for at least an hour before serving.
Interesting Facts
This cake can be served frozen or thawed slightly for a soft-serve texture.
This cake can be topped with caramel sauce, chocolate sauce, or other toppings for added flavor.
This cake can be made ahead of time and stored in the freezer for up to a month.