Tender semi-homemade vanilla cake layers filled with creamy vanilla buttercream and white chocolate ganache dripping down the sides of the cake.
Preheat oven to 350 °F. Spray four 6-inch round cake pans with non-stick spray, line the bottom of each pan with parchment paper, and spray again. Set aside.
In a medium-size bowl, whisk and stir together the cake mix, all-purpose flour, and salt. Set aside.
In the stand mixer bowl fitted with a paddle attachment, beat the butter, oil, and sugar on medium-high for 5 minutes.
Add eggs, one at a time to the stand mixer bowl and beat on medium until well incorporated.
Turn the mixer on low and add half of the flour mixture to the butter mixture until fully incorporated.
Add the vanilla and milk and beat on low until incorporated. Scrape down the sides of the bowl. Finish by adding the remaining flour mixture and mix on medium for another 30 seconds.
Evenly distribute the cake batter among the three cake pans and bake for about 30-35 minutes or until a toothpick inserted into the center of each cake comes out clean or with just a few moist crumbs.
Remove cakes from the oven and let cool in pans for 10 minutes before inverting onto cooling racks to cool completely. Wrap cakes in plastic wrap and place into the freezer to chill for 30 minutes.
In the stand mixer bowl fitted with the paddle attachment, beat the butter until light and fluffy, about 2 minutes.
Turn the mixer to low and gradually add the powdered sugar, followed by the cream, salt, and vanilla extract. Mix until combined. Mix until incorporated completely. Scrape down sides of the bowl.
Add 1-2 drops of ivory gel food coloring to dye the buttercream a light ivory color.
Turn the mixer to medium-high and beat the frosting for about 5 minutes until light and fluffy. Turn the mixer on low and mix for 2 minutes to push out any air bubbles.
In a medium glass bowl, melt ivory chocolate candy melts and water in the microwave. Heat for 30 seconds at a time until the chocolate candy melts have mostly melted.
Then mix with a rubber spatula. Continue to mix until the chocolate and water are well combined and streak-free. If there are chunks of chocolate, melt for 10 seconds at a time until the chocolate is fully melted or pour the chocolate into a fine mesh sifter to remove any chocolate lumps.
Pour the chocolate into a squeeze bottle for a comfortable grip for decorating. If chocolate drip becomes too cold and hardens, then heat in the microwave for 5-10 seconds, shake or stir to make sure its all the same temperature. Don't overheat or chocolate will separate, and you'll have to remix.
Remove the cake layers from the freezer and unwrap the cake layers. Next, use a serrated knife to cut off the dome of the cakes to make the layers flat and even.
Add a small amount of buttercream onto the center of the cake board. Layer one vanilla cake, cut side up onto cake board. Add a 2/3 cup of vanilla buttercream over the cake.
Place another cake layer cut side down over the top. Repeat the process for another layer — Crumb coat with ivory vanilla buttercream and freeze for 30 minutes.
Add a thick layer of ivory buttercream all over the cake. Use an offset spatula to fill in any gaps with more buttercream. Then use a cake scraper to smooth out the sides of the cake. Use the offset spatula to make the top edges sharp and smooth.
Add the ivory chocolate water ganache is dripping down the sides and the top of the cake. Use a small offset spatula to smooth out the ganache on top.
Add a second and third layer of ivory ganache around the edges of the cake. Build layers upon the previous ganache layers.
Place cake in the freezer for 10-15 minutes to set the precious ganache layers.
Continue to build layers two at a time and freeze in between until you have 8 layers of ganache total.
Use a wooden skewer to create a hole in the center and place the candle into the hole. Light candle and serve the cake at room temperature.