Soft and sprinkle-studded Christmas Funfetti Sheet Cake with Festive Vanilla Buttercream. This is the cutest Christmas sheet cake! It reminds me of Whoville and all things bright and cheery for this holiday season.

10 Sheet Cakes for Christmas Series

We’re back again with another fun sheet cake recipe leading up to Christmas. Welcome to cake #5 out of 10! We still have 5 more delicious cakes to share with you. So far we have my now-viral Eggnog Tres Leches Cake with Nutmeg Whipped Cream, Chocolate Peppermint Sheet Cake,  Red Velvet Hot Chocolate Sheet Cake, Gingerbread Cake with White Chocolate Buttercream, and ever-popular Little Debbie Christmas Tree Sheet Cake. With 5 more still on the way, you’re sure to find a sheet cake that will fit your comfort level, as well as taste absolutely mouthwatering for your guests this holiday season. There’s so much already on your plate – lets dive right into my newest creation: Christmas Funfetti Sheet Cake!

How to make a Christmas Funfetti sheet cake:

My funfetti sheet cake (made with a doctored cake mix) simply can’t be beat! Bakers from all around the globe use it in the bakeries and home-bakes for the perfectly tasty results this recipe gives them every time. It starts with a box mix, and then we add a bunch of ingredients to it for the best taste and texture. Doctored Cake Mixes are celebrated and used by bakers all around, and I cannot wait for you to try this funfetti version. Let’s dive right in!

Here’s what you’ll need (the quantities are with the recipe at the bottom of this post!):

  • Buttermilk
  • Sour Cream
  • Eggs
  • Vegetable Oil
  • Vanilla
  • Christmas Sprinkles
  • White Cake Mix

That’s it! Whisk everything in a bowl together, sift in the cake mix and stir in the sprinkles, then bake! Let it cool in the pan, then we’ll add on all those festive buttercream designs.

How to make vanilla buttercream

Making my vanilla buttercream is pretty straightforward. Here’s what you’ll need (the exact quantities are below with the printable recipe).

  • Unsalted Butter
  • salt
  • vanilla
  • heavy cream
  • powdered sugar

Whip up the butter until it’s light and fluffy, then add in the salt, vanilla, and heavy cream. Add in the powdered sugar after everything is combined, then whip it all up until it’s light and fluffy in texture.

How to make the buttercream design on a sheet cake

This design uses colored vanilla buttercream and lots of fun piping tips! Here’s what I used for each color:

  • 1M (large star) for the red
  • 1A (large circle) for the pink
  • 6B (large french tip) for white
  • 125 (pedal/ruffle) & #32 (smaller star)for the light green

Start by piping on the large rosettes and 6B swirls. Pipe in a few drop circles (pink) in clusters, then add in the ruffles and pipe in other shapes to fill everything in. Add on the silver dragees, if desired.

Where do I find that sheet pan?

I found mine on Amazon – here.

How to store the sheet cake?

I just place the sheet cake into the freezer until the buttercream is firm, then wrap it all up with plastic wrap and keep it in the freezer until the night before serving. I place it in the fridge that morning and it’s ready to go by the evening!

Where can I find the Christmas sprinkles?

I found this variety at Walmart, and the silver Dragees (not exactly eatable, but edible, if that makes sense) from Amazon.

Here’s a quick video of the process:

I hope you enjoy my newest sheet cake here for my 10 SHEET CAKES FOR CHRISTMAS series! It’s been so fun so far, and there’s many more to come. If you make my cake or a creation inspired by it, I’d love to see it. Make sure to tag me @bakingwithblondie or #bakingwithblondie so I can join in on all the fun.

Happy Baking!

xo, Mandy

Get the Recipe: Christmas Funfetti Sheet Cake

Soft Funfetti Cake Layers frosted in bright and festive vanilla buttercream designs.
Servings: 12 servings
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Ingredients
 

Funfetti Sheet Cake

  • 3/4 cup buttermilk, room temperature
  • 2/3 cup sour cream, room temperature
  • 4 large egg whites , room temperature
  • 1/3 cup vegetable oil
  • 1 Tablespoon vanilla
  • 1/2 cup Christmas jimmies/sprinkles
  • 1 15.25oz Box White Cake Mix, I used Duncan Hines

Vanilla Buttercream

  • 1 1/2 cup (or 3 sticks) Unsalted Butter, let sit out for 10 minutes
  • 1 pinch salt
  • 1 Tablespoon vanilla
  • 1/2 cup heavy cream
  • 7-8 cups powdered sugar
  • colored gel coloring (red, pink, and light green)

Extras

  • 1 Tablespoon silver dragees

Equipment

  • 9×13 sheet cake pan
  • Piping tips and piping bags 1M (large star), 1A (large circle), 6B (large french tip), #125 (pedal/ruffle), #32 (smaller star)
  • pink, red, and green gel colors

Instructions
 

For the Funfetti Cake

  • Preheat the oven to 325 degrees, and prep a 9×13 sheet pan/dish with shortening/spray/goop/nonstick. Set aside.
  • In a large bowl, whisk together all the ingredients except for the cake mix and sprinkles. Sift in the cake mix, then gently fold in the sprinkles until combined. Spread into the prepared 9×13 pan and bake for 20-14 minutes. Let cool.

For the Buttercream

  • In the bowl of a stand mixer, whip up the butter until it's light and fluffy, about 2 minutes. Add in the salt, vanilla, and heavy cream and whip up again to combine. Add in the powdered sugar and whip up on low speed until combined, then on high speed for 2 minutes to lighten the texture.
  • Split the buttercream into 4 bowls and tint three of the bowls pink, red, and light green using the gel coloring. Add the buttercream to piping bags fitted with the following piping tips: 1M (large star), 1A (large circle), 6B (large french tip), #125 (pedal/ruffle), #32 (smaller star).
    You can make the colors any tips you'd like, but here's what I did:
    Red: 1M
    Pink: 1A
    Light Green: #125 and #32
    White: 6B
  • One by one, pipe on rosettes, swirls, drop stars, and ruffles in a random pattern all over the top of the cake. Sprinkle on the silver dragees.
Author: Mandy Merriman – Baking with Blondie