Read through the full directions and watch the video tutorial below before beginning. If you wish to make the cake ahead of time, read my Make-Ahead Instructions below before beginning.

Preheat oven to 350°F (177°C). Grease two 9-inch cake pans, line with parchment paper rounds, then grease the parchment paper. Parchment paper helps the cakes seamlessly release from the pans. (If it’s helpful, see this parchment paper rounds for cakes video & post.)

Whisk the cake flour, baking powder, baking soda, and salt together. Set aside.

Using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter and sugar together on high speed until creamed, about 2 minutes. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed. Add the egg whites, sour cream, and vanilla. Beat on high speed until fully combined and mixed, about 2 minutes. Scrape down the sides and up the bottom of the bowl as needed. Pour the dry ingredients into the bowl. Then with the mixer running on low, slowly pour in the milk. Do not over-mix. You may need to whisk it all by hand to make sure there are no lumps at the bottom of the bowl. The batter will be slightly thick.

Pour batter evenly into cake pans. Bake for around 24-25 minutes or until the cakes are baked through. To test for doneness, insert a toothpick into the center of the cake. If it comes out clean, it is done. Cool cakes in the pans set on a wire rack for 30 minutes, then remove the cakes and cool completely directly on a wire rack. The cakes must be completely cool before frosting and assembling.

In a large bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed until creamy, about 2 minutes. Add confectioners’ sugar, milk/cream, vanilla extract, and salt with the mixer running on low. Increase to high speed and beat for 3 full minutes. Taste. Add a pinch of salt if frosting is way too sweet. Frosting will be thick.

Place 1 cup + 2 Tablespoons (about 1 heaping cup or 275g) of frosting into a medium bowl. This will remain white and be used for the cake’s filling and to form Elmo’s eyes and nose. Place 1/3 cup (about 85g) of frosting into a small bowl. Stir in 3 drops of black gel food coloring until it’s dark gray. (Keep in mind that frosting dries darker.) Tint the remaining frosting red using about 4-5 big drops of red gel food coloring. Tint until you are satisfied with the color. Remember, frosting dries darker.

Using a large serrated knife, slice the domes off the cooled cakes (a semi-thin layer) to create a flat surface. Place tops into a bowl to use in step 9. Place 1 cake layer on your cake stand, serving plate, or cake turntable. Spread 1 cup (about 250g) of white untinted frosting all over the top. (Reserve remaining white frosting for step 9.) Top with 2nd layer. Spread a thin layer of red frosting around the sides and top of the cake. This is your crumb coat and should be a pretty thin layer. An icing spatula and bench scraper are helpful for this. See video tutorial below. Chill uncovered in the refrigerator or freezer for at least 30 minutes to help set the crumb coat.

Crumble the pieces of cake that you leveled off into crumbs. I just use my hands for this. Stir in 1 Tablespoon of white frosting. If the mixture still seems pretty crumby and dry, add a little more of the white frosting until you have a moist mixture that you can form into shapes. Mixture shouldn’t be overly wet. Form into 3 shapes: two 2-inch discs for Elmo’s eyes and one 3-inch oval/egg shape for Elmo’s nose. Smooth them out as best you can. Place on a lined baking sheet and chill in the refrigerator or freezer for at least 30 minutes to set. Once they’re set, you can smooth out any bumps on the surface with your hands if needed.

First, spread a thin layer of black frosting on the bottom half of the top of the cake. Use a small offset spatula to help ensure it’s perfectly smooth. Reserve remaining black frosting. Using a toothpick, trace/outline Elmo’s mouth shape within the black frosting. Use it as your guide for piping his fur around it. Fit your piping bag with Wilton piping tip #233 (grass tip). Spoon some red frosting inside. It’s difficult to pipe this frosting if the bag is over-filled, so just work with a little bit of frosting in the bag at a time. Place the tip directly on top of the cake’s surface and apply pressure to squeeze the frosting out of the tip. Quickly lift the tip up while squeezing the frosting out. The video tutorial below is helpful for this step. Pipe his fur all over the top and sides of the cake. (The sides are optional, but if you have enough frosting, go for it!) It’s helpful to carefully tilt the cake stand/turntable so you can more easily pipe frosting on the sides. Set cake aside. You can refrigerate uncovered if desired as you finish Elmo’s eyes and nose.

You can melt the chocolate and oil together in a double boiler or the microwave. If using the microwave: place the chopped chocolate and oil in a medium heat-proof bowl. Melt in 20 second increments in the microwave, stirring after each increment until completely melted and smooth. Place one of the discs (eyes) into the white chocolate. Use a fork to help fully coat it. Using a fork, lift the disc (eye) out of the chocolate. Place back onto lined baking sheet. Repeat with 2nd disc (eye). Stir 1 drop of orange gel food coloring into the remaining melted chocolate. Coat Elmo’s nose just how you coated the eyes. Refrigerate or freeze for 20 minutes or until white chocolate has set. I find the orange becomes a little darker as it dries.

After the white chocolate sets, fit your piping bag with Wilton tip #12 (round tip). Spoon some black frosting inside. Pipe Elmo’s pupils onto the eyes. Carefully press the eyes and nose on top of the cake to form Elmo’s face.

If you decorated the cake on a cake turntable, use a couple thin spatulas (and a helper!) to carefully lift the cake off the turntable and onto a cake stand, server, or cake carrier base. I actually like to use a cake carrier to cover and store my cakes in the refrigerator.

Serve cake. Cover leftover cake tightly and store in the refrigerator for up to 5 days.