Vanilla Sheet Cake

• Preheat the oven to 350°F. Grease a 9×13-inch baking pan and line it with parchment paper.
• In a stand mixer fitted with the paddle attachment, combine the cake flour, sugar, baking powder, baking soda, and salt.
• Add the softened butter and mix on low speed until the mixture resembles fine, damp crumbs.
• In a separate bowl, whisk together the eggs, egg whites, buttermilk, oil, and vanilla extract until combined.
• Gradually pour the wet ingredients into the dry ingredients, mixing on low speed. Scrape down the sides of the bowl as needed and mix until the batter is smooth and combined. Avoid overmixing.
• Pour the batter into the prepared pan and spread evenly. Bake for 30–40 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
• Allow the cake to cool completely before frosting.

Vanilla Buttercream Frosting

• In a stand mixer fitted with the paddle attachment, beat the softened butter on medium-high speed for 3–5 minutes until light and creamy.
• Gradually add the powdered sugar, mixing on low speed until fully combined.
• Pour in the vanilla extract and heavy cream. Increase the speed to medium-high and beat for another 2–3 minutes until smooth and fluffy.
• Spread the vanilla buttercream evenly over the cooled sheet cake. Reserve some buttercream for piping decorations, if desired.

Small Batch Royal Icing

• In a mixing bowl, combine the powdered sugar, meringue powder, corn syrup, vanilla extract, and 1 tablespoon of water.
• Beat on low speed until combined, then increase to medium-high speed and mix for approximately 5 minutes until smooth and glossy.
• Add more water, a few drops at a time, until the icing reaches your desired piping consistency.
• Divide the royal icing into small bowls and mix in your desired gel food coloring.
• Transfer the royal icing to small piping bags and decorate the Teddy Grahams with Halloween costumes, such as ghosts, pumpkins, and skeletons. Allow the royal icing to dry completely before placing them on the cake.

Assemble and Decorate

• Spread an even layer of vanilla buttercream over the completely cooled vanilla sheet cake.
• Arrange the decorated Halloween Teddy Grahams across the cake, gently pressing them into the buttercream.
• Use the reserved buttercream to pipe small pumpkins or other Halloween designs to fill the empty spaces.

Serve. Slice the cake into 15 pieces and enjoy!