Vanilla cake with red, white and blue vanilla buttercream, blue chocolate ganache drip, and patriotic sprinkles.
Preheat the oven to 350 °F. Spray three 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 flour, baking powder, 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 the eggs, one at a time to the stand mixer bowl and beat on medium until well incorporated.
Turn the mixer on low and add the flour mixture to the butter mixture until fully incorporated.
Pour in the buttermilk and vanilla extract. Mix on medium for another 30 seconds and scrape down the sides of the bowl.
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 them into the freezer to chill for 30 minutes to 1 hour.
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 add the salt and vanilla.
Next, gradually add powdered sugar, followed by the cream. Mix on medium-high speed for about 5 minutes, until light and fluffy. Scrape down the sides of the bowl.
Divide the buttercream into two parts then save one half from staying white. Then divide the remaining half into two parts and color each half with super red and royal blue gel food coloring.
Place ½ cup of each buttercream into its piping bag fitted with #844 star tip.
Please note, before using, turn the mixer on low and mix for 2 minutes to push out any air bubbles or use a rubber spatula to push out the air bubbles. (You may need to repeat this step when frosting the outside of the cake).
In a medium glass bowl, melt navy blue 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 with a hand whisk.
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 the chilled vanilla cake, cut side up onto the cake board.
Then pipe a ring of blue buttercream in the center followed by a ring of white and red buttercream. Continue to add a ring of white buttercream then use an offset spatula to smooth it.
Place another cake layer cut side down over the top. Repeat the process for another layer — Crumb coat the whole cake with white buttercream and freeze for 30 minutes.
Starting from the bottom, while spinning the cake, squeeze consistent pressure on the piping bag with white buttercream, pipe two rows.
Next, pipe two rows of red buttercream followed by two more rows of white buttercream and repeat until the sides are fully covered. Then add white buttercream on top of the cake.
Use a cake scraper to make the cake smooth on the top and sides. Use the offset spatula to add more buttercream to fill in any gaps. Repeat the process until the sides are smooth.
Place the cake on top of a baking tray then add patriotic sprinkles to the bottom third of the cake.
Add the blue ganache drip to a squeeze bottle and drip the ganache over the sides and on top.
Finally, pipe red, white, and blue buttercream swirls on top of the cake. Sprinkle patriotic sprinkles on top of the cake. Serve the cake at room temperature.