Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing them lightly and dusting with flour.
In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until combined.
In another bowl, combine the eggs, buttermilk, oil, and vanilla extract, whisking until fully incorporated.
Pour the wet ingredients into the dry ingredients and mix until just combined, then fold in the chocolate chips.
Divide the batter evenly between the prepared cake pans and smooth the tops with a spatula.
Bake in the preheated oven for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Once baked, remove the cakes from the oven and let them cool in the pans for about 10 minutes before transferring to a wire rack to cool completely.
While the cakes are cooling, prepare the frosting by creaming the butter until light and fluffy.
Gradually add the powdered sugar and cocoa powder, mixing well after each addition, then add the heavy cream and vanilla, mixing until smooth.
Once the cakes are completely cool, place one layer on a serving plate and spread a layer of frosting on top.
Carefully place the second layer on top and frost the top and sides of the cake with the remaining frosting.
Decorate as desired, perhaps with additional chocolate shavings or even sprinkles for an extra indulgent touch.
Slice the cake into wedges and serve to enjoy your delightful double chocolate indulgence!
