Preheat the oven to 350 F. Grease and line a 9-inch cake pan with parchment paper.

In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.

In a medium bowl, whisk together the eggs, vegetable oil, and milk.

Add the egg mixture to the flour mixture in thirds, mixing with a spatula after each addition.

Pour the batter into the prepared cake pan, filling about halfway.

Bake for 45-50 minutes or until a toothpick inserted in the center comes out clean.

Cool the cake in the pan for 15 minutes before transferring to a wire rack to cool completely.

Using a serrated knife, trim the top of the cake off so that it’s flat and even. Then, cut the cake into rounds using a round cookie cutter that matches the size of your mousse mold (ex: 2 ½ to 3 inches in diameter). If the cake rounds seem too thick, cut them in half horizontally so they are about ½ inch thick.

Place cake rounds in an airtight container and keep in the refrigerator until ready to assemble.

Place the chocolate in a heatproof bowl and set aside.

Combine the gelatin and cold water in a small bowl and stir until dissolved.

Place the milk in a small saucepan and bring to just under a boil. Whisk in the gelatin mixture.

Pour the milk mixture over the chocolate and let it stand for 30 seconds. Gently whisk the mixture until it is smooth.

Whip the heavy cream on medium high speed until it reaches soft peaks, about 5 minutes.

While the chocolate mixture is still warm, slowly pour it over the whipped cream, a little at a time, folding it in with a spatula.

Scoop the mousse into the small dome molds and let set in the refrigerator for 1-2 hours.

Combine the gelatin powder and water in a small bowl, stirring until dissolved. Set aside.

In a small bowl, whisk together the egg yolks and salt. Set aside.

Melt the white chocolate in a double boiler over low heat. Add ¼ cup heavy cream, a little at time, stirring until smooth and warm.

Melt the gelatin mixture in the microwave for 15 seconds and stir into the chocolate mixture, whisking constantly.

Continue whisking for 1 minute. Remove from the heat and place in the refrigerator until the mixture comes to room temperature, about 20 minutes.

Whip the heavy cream on medium high speed until it reaches soft peaks.

Whisk the cooled chocolate mixture briefly and then fold it into the whipped cream.

Pour the mousse into the medium dome molds, filling ⅔ -¾ full.

Pop the dark chocolate mousse domes out of their molds and gently press one into each white chocolate mousse dome. Let set in the freezer for at least 4 hours.

To make the chocolate ears and tail: Place some chocolate candy melts into a piping bag and melt in the microwave, checking every 30 seconds. Pipe chocolate rounds and tails onto a piece of wax paper. Let set.

To make the fondant buttons: Roll out a piece of yellow fondant. Cut out ovals using a sharp knife. Place on a piece of wax paper and set aside.

To make the fondant trim: Take a medium sized piece of black fondant and roll it into a rope that will fit around the circumference of one cake. Place on a piece of wax paper and roll flat using a fondant roller or rolling pin. Trim the sides into straight lines using a sharp knife. Repeat so you have one piece of fondant trim for each cake.

Place the chocolate in a heatproof bowl. Set aside.

Combine the water, sugar, and sweetened condensed milk in a small saucepan and bring to boil. Boil for 1 minute and then remove from the heat.

Fill a large bowl with 8 cups of cold water. Place the gelatin sheets in the water and let rest for 5 minutes. Remove the gelatin sheets from the water, squeezing out any excess water.

Add the gelatin sheets to the sugar mixture and stir until combined.

Pour the sugar mixture over the chocolate and let it sit for 2-3 minutes.

Using an immersion blender, slowly blend the chocolate and the sugar mixture together. Make sure not to lift the blender and create excess air bubbles.

Once combined, pour the mixture through a sieve into a large liquid measuring cup or other vertical container to remove the air bubbles. If you have a lot of bubbles, you can also press a piece of plastic wrap on top of the mixture and then remove it.

Gently stir in the desired amount of red gel food coloring, making sure the color is evenly distributed.

Cover the mixture with plastic wrap and let cool at room temperature, stirring occasionally, until it reaches 90-96 degrees. Keep it covered until ready to assemble the cakes.

Place a wire rack on top of a baking sheet.

Place the cake rounds on top of the wire rack.

Carefully unmold the mousse domes and place one dome on top of each cake round.

When the mirror glaze has cooled to the right temperature, pour it over each dome making sure all sides are covered. Repeat with additional coats of mirror glaze as needed.

Wrap the black fondant trim around the bottom of each cake, covering the chocolate cake. Gently press two yellow ovals onto the front of the cake. Press two chocolate rounds and one chocolate tail into the top of the cake (smooth side out).