Giant Heart Sunglasses Cake - yellow cake

Method

• For the Cake:
• Preheat oven to 350 degrees F. Spray two 9-inch square cake pans with nonstick spray. Line the bottom with parchment paper and spray with nonstick spray.
• Prepare cake mix per package directions, adding in the packages of vanilla pudding mix.
• Scoop 2 1/2 cups of batter into a small bowl. Scoop another 2 1/2 cups of batter to another small bowl.
• Color one of the small bowls a dark blue shade, folding in about 1 1/2 teaspoons of Deep Blue gel coloring.
• Color the other small bowl to a light blue shade, folding in about 1/2 teaspoon of Deep Blue. You should have white, dark blue, and light blue batters.
• Using a small ice cream scoop, drop alternating scoopfuls of the batter colors into the cake pans, dividing evenly. Swirl the batter with a wooden popsicle stick, making sure to get all the way down to bottom of the cake pan.
• Bake for 35-40 minutes or until a toothpick comes out clean. Transfer to a wire rack and let cool 20 minutes. Invert onto a wire rack and let cool completely. Wrap each square cake in plastic wrap and freeze overnight.
• Print a large sunglasses stencil online and cut in half, dividing the two frames. Unwrap the frozen cakes on a wooden cutting board and position the stencil halves on top. Trim around the stencils, with a sharp paring knife.
• Transfer trimmed cakes to a large cake board or platter, matching up halves to create one large pair of sunglasses.
• Frost the cake with a crumb coat of pink frosting. Chill in fridge or freezer for about 10-15 minutes or until frosting is hard to the touch.
• Meanwhile, cut the lenses out from stencil. On a surface lightly dusted with cornstarch, roll out the yellow fondant using a silicone rolling pin. Place one of the heart lenses on top and carefully cut out using a sharp paring knife. Place on a parchment-lined baking sheet. Repeat with the other heart lens.
• Transfer some of the pink buttercream to a piping bag fitted with a #803 tip. Frost cake all over with buttercream, using the piping bag to apply on the sides. Smooth out with a small offset.
• Place back in the fridge or freezer about 10-15 minutes or until the frosting is hard to the touch.
• Using a non-patterned sheet of paper towel, gently smooth out frosting, buffing out any harsh lines or imperfections. Position fondant heart lenses into place.
• Let cake sit out to room temperature before serving, about 30-45 minutes.
• For the Lemon Swiss Buttercream:
• Prep everything first!
• Bring a small saucepan with an inch of water to a simmer.
• Whisk egg whites and sugar together in a stand mixer metal bowl and attach a thermometer.
• Set the bowl over the simmering water, making sure the bottom is not touching the water. Whisk constantly and allow the mixture to reach 160°F.
• Immediately transfer bowl to a stand mixer fitted with a whisk attachment and whisk on high until stiff peaks and glossy and doubled in size, about 10 minutes.
• Switch to the paddle attachment and drop speed to medium. Add in a couple chunks of butter at a time, fully incorporating before adding more.
• Once all the butter is mixed in, increase speed to medium-high and beat until smooth. Then beat in extracts and salt.
• Fold in about 1/2 teaspoon Deep Pink gel food coloring with a spatula.