Christmas Funfetti Sheet Cake

How to Make Christmas Funfetti Sheet Cake

What is a Funfetti Cake?

Also sometimes called a Confetti Cake, Funfetti is a soft vanilla-flavored cake with sprinkles mixed into the batter. It’s a super fun cake reminiscent of childhood birthday parties – but this one is homemade! It’s SO much more flavorful than a box mix – and we’re using Christmas-colored sprinkles in the batter and on top to decorate to make this a super festive cake, perfect for the holidays.

How to Make MOIST Funfetti Cake

• Correctly measure your flour. Be sure to measure your flour correctly by weighing it with a digital scale. If you don’t have one, use the spoon and level method (learn more about that here) to avoid a dry, dense cake. 
• Don’t lower the sugar. Sugar does so much more than just sweetening – learn more about sugar’s role in baking here. 
• Use the correct flours. We are using a combination of all-purpose flour and cake flour to ensure our cake is light and fluffy. More on this below.
• Use real buttermilk. Your cake won’t be the same if you use a buttermilk substitution. More on buttermilk just below.

What if I Don’t Have Buttermilk?

Buttermilk works best in this recipe to provide a rich and tender cake. You can learn more about the science of buttermilk in my Buttermilk 101 article here. I would not recommend using a buttermilk substitute. Buttermilk is thinner than yogurt, less fatty than cream, and more acidic than milk. If you must, use whole milk instead but note the cake’s final taste and texture will be different.

Why Use Sour Cream in Cake? Can I Substitute the Sour Cream?

This also adds such a lovely richness and balance of flavor to the Christmas Funfetti Sheet Cake. The combination of buttermilk and sour cream is the best of both worlds! They both help make the cake ultra moist and tender. Be sure to use full-fat sour cream that’s at room temperature. Full-fat plain Greek yogurt also makes a fine substitute if you don’t have sour cream. I haven’t tested any dairy-free substitutes.

Do I Have to Use Half Cake Flour? Can I Use all All-Purpose Flour Instead?

I wanted this cake to have a very soft texture, but still give it some structure and avoid any sponginess – so I went with a mix of cake flour and all-purpose flour. I really recommend sticking with this combination for this recipe. If you don’t have access to cake flour, or want to avoid purchasing it, this cake will probably still work with all-purpose flour only; just know that we haven’t tested this, and the cake will not be as light and fluffy as a result.

Avoid using DIY cake flour substitutions, as they simply don’t work as well. Just take a look at the differences between the cupcakes in the image below. Check out my Cake Flour 101 article here to understand why.

What Type of Cream Cheese is Best for Frosting?

Use a regular full-fat cream cheese brick at room temperature. Do NOT use whipped or spreadable cream cheese made for bagels. I’ve found that some off-brand cream cheese bricks have an unappealing, almost watery texture. Go with a quality brand when possible, such as Philadelphia cream cheese.

Why I Prefer Organic Powdered Sugar for My Frostings

For the absolute smoothest frosting, I recommend investing in organic powdered sugar that contains tapioca starch instead of cornstarch because it dissolves much more readily – so no grittiness! It’s still necessary to sift the powdered sugar after measuring it, and before adding it into the mixing bowl. This will ensure no pesky lumps and clumps ruin the smoothness of your frosting. This is the brand of organic powdered sugar I usually use.

What Type of Sprinkles Should I Use?

• I used red, green, and white jimmies
• Feel free to use whatever sprinkles you prefer – just keep in mind that nonpareils (the tiny round sprinkles) will remain hard and super crunchy in the cake, even once baked, and they often also bleed into the batter – so I recommend avoiding those.
• Make sure to smell and taste your sprinkles if they’ve been in your cupboard for a while before adding them to the batter to ensure they’re not expired!
• Please also note that some sprinkles will bleed a little when mixed into the batter, or even as they bake. That’s okay – it will still taste great, but I like these Wilton brand jimmies because they won’t bleed when mixed or baked.

What Kind of Pan Should I Use?

This recipe was written for a 12×17-inch half-sheet metal pan. This is my go-to pan I recommend (it even comes with a lid for super easy transporting – or it’s also available without). However, if you want something more festive, this is the pan (in the shade ‘broccoli’) used in these photographs!

Can I Bake this in a 9×13 Cake Pan?

Yes, this recipe has been tested in a 9×13-inch metal pan too (not glass). After 25 minutes of baking at 350°F, tent the cake with foil to prevent over-browning on the top and sides. If your oven has hot spots, rotate your pan at this point. Bake for an additional 10 minutes longer, or until the cake is slightly pulling away from the edges, the top is lightly golden brown, the center is set, and a toothpick inserted in the center comes out clean. If the center of your cake still appears a little greasy and doesn’t spring back up when pressed, that’s normal! The residual heat from the pan will continue to bake your cake after removing from the oven. If you wait until the center of your cake springs back when pressed, your cake will be overbaked and dry.

Can I Use a Glass Pan for This Cake?

I really recommend using a metal pan such as this one for this cake. Glass is not a great conductor of heat, so the edges of the cake will become overcooked and dry before the center can cook through. Aluminum baking pans conduct heat faster and more evenly, and will give your cake a nice even bake, without drying it out. If you absolutely must use a glass pan, drop the temperature to 325°F and increase the bake time by 5 to 10 minutes, baking until a toothpick inserted in the center comes out clean.

Can I Halve This Recipe?

Yes! Bake in a quarter sheet metal pan for 18-20 minutes, or until the top is lightly golden brown and a toothpick inserted in the center comes out clean.

How to Store this Christmas Funfetti Cake

Store the cake tightly wrapped in plastic wrap or placed inside an airtight container in the fridge for up to 3 days. This cake must stay refrigerated, as the cream cheese frosting contains dairy and it will spoil if stored at room temperature.

If you’ve already sliced the cake into individual portions, exposed cake dries out much quicker than if it’s stored unsliced. Place each slice in to-go containers (like these) or an airtight container with a piece of wax paper or parchment under each slice to come up the sides.

Can I Make This Christmas Funfetti Sheet Cake Ahead of Time?

Yes! After the cake has cooled, cover the unfrosted top with parchment, then wrap the entire pan with plastic wrap before refrigerating, up to 3 days ahead of time. While best enjoyed on the day of frosting the cake, this cake can also be baked and frosted up to 2 days ahead of time – just be sure to store the cake inside an airtight container or wrapped well in plastic wrap to avoid it drying out.

The frosting can also be made ahead of time, transferred to an airtight container, and stored in the fridge for up to 3 days. Bring to room temperature and re-whip with an electric mixer before using.

Can You Freeze This Christmas Funfetti Sheet Cake?

We haven’t tried that, but I don’t see why not! Wrap slices of Christmas Funfetti Sheet Cake well in plastic wrap and store inside a ziptop bag or an airtight container for up to a month. I recommend freezing without the frosting, and frosting once the cake is thawed, for best results. Thaw the cake overnight in the fridge before decorating.