UNDER-THE-SEA CONFETTI CAKE

Steps:

• For the confetti cake: Preheat the oven to 350 degrees F. Prepare three 10-inch cake pans by spraying them with cooking spray, then place a parchment paper circle in each cake pan, then spray again (this will make sure the cake layers don't stick). Preheat your oven to 350 degrees F.
• In a large bowl, sift the flour and baking powder together; this will make sure everything gets distributed nice and evenly in the batter. Set aside.
• In the bowl of a stand mixer fitted with the paddle attachment, beat the sugar, butter and salt on medium-high speed until it's nice and fluffy and light in color, 8 to 10 minutes, stopping a few times to scrape down the bowl and paddle with a rubber spatula.
• Reduce the speed to low and add the eggs one at a time, beating until completely combined and scraping down the sides of the bowl between additions. Increase the speed to medium-high for about 30 seconds once all the eggs are incorporated. Scrape down the bowl.
• Add the vanilla to the milk. Reduce the mixer speed to low. Alternating between the flour mixture and milk while the mixer is running, add half of the flour to the bowl and mix until combined, scrape the bowl, then add half the milk, scrape the bowl, then the remaining flour, scrape the bowl, then add the remaining milk. Scrape down the bowl. Scrape the batter off the spatula-don't bang the spatula on the side of the bowl, as that will knock the air out of the batter! Gently fold in the sprinkles by hand with the spatula.
• Gently spoon the batter evenly into your prepared pans. Smooth the tops with a spatula. Bake until a toothpick inserted in each cake comes out with no crumbs sticking to it, 30 to 35 minutes. Cool the cakes on a wire rack for 10 minutes in the pans. Remove the cakes from the pans and cool completely on the rack, about 1 hour.
• For the American buttercream: On medium speed, beat the butter, vanilla and salt together in the bowl of a stand mixer fitted with the whisk until combined. Stop the mixer and add the confectioners' sugar 2 cups at a time, beating on low speed to combine. Stop the mixer and scrape down the bowl between each addition. Beat in the milk in 2 additions on low speed, then increase the speed to medium-high and whip until the mixture is light and fluffy. Add more milk a tablespoon at a time if the frosting seems too thick.
• To assemble the cake: Level the tops of the cake layers with a serrated knife or cake leveler. Adhere one of the cake layers to a cardboard cake round or cake plate with a dab of frosting to hold it in place. Frost the top of the layer with about 1 cup of the buttercream. Stack the second layer on top and repeat. Add the third layer and frost the top and sides with a thin coat of the buttercream (this is a crumb coat). Refrigerate until the frosting is firm, 20 to 30 minutes.
• Frost the top and sides of the cake with a thicker layer of buttercream and refrigerate again until very firm, about 1 hour.
• For the decorations: Lightly dust a work surface with cornstarch and roll out the blue fondant to a large circle about 22 inches in diameter and about 1/8-inch thick. Drape the rolled fondant over the top of the cake. Working from the top down the sides, lightly press and smooth the fondant over the cake with either a fondant smoother or your hands. Pop any air bubbles with a cake tester or toothpick and continue to smooth. Trim the excess fondant from the bottom of the cake with a pizza cutter. Set aside.
• Make waves from the green fondant by rolling some of the fondant into about a 4-inch-long tapered rope and curling in the tapered end to the base, making a spiral. Lightly flatten and trim the bottom of the wave to make a clean edge. Continue making more waves. Adhere the waves by dabbing a drop of water onto the backside of each and lightly pressing them around the base of the cake.
• Make clouds from the white fondant by making a small 1-inch ball of the fondant, press 1 gumball into the center and 2 to 3 more gumball around to make a cloud shape. Roll out another piece of the white fondant ⅛-inch thick and cover the gumballs, lightly pressing around, trim any excess from the bottom (save the trimmings for the octopus tentacles) and tuck the edges under to make a cloud shape. Continue making more clouds. Adhere the clouds around the sides of the cake, above the waves, with a dab of water.
• Make octopus tentacles by taking a piece of the red fondant and rolling it into a hot dog shape. Take a small piece of the pink fondant and roll it into a thin rope the same length as the red fondant and lightly flatten it with the heel of your palm. Press the pink fondant onto the red fondant, then roll it into a tapered rope about 10 inches long so it has a pink stripe on it. Continue making more tentacles.
• To make the suction cups for the tentacles, take little pieces of the white fondant and roll them in balls about the size of peas or small blueberries and make a little dimple in the center with the end of a ball tool. Adhere the balls along the pink stripe on each tentacle with little dabs of water. Attach the tentacles to the cake with dabs of water, or make it look like they are coming out of the top of the cake by using skewers.