Funfetti Crumb Cake

If coffee cake and birthday cake had a baby, it would be this Funfetti Crumb Cake.

This soft vanilla cake is packed with colorful rainbow sprinkles and topped with a thick, buttery crumb topping that practically melts in your mouth. It has all the cozy, bakery-style goodness of a classic crumb cake, but with a funfetti twist that makes it perfect for birthdays, celebrations, or honestly just a random Tuesday when you need a little extra joy.

The cake itself is soft and tender thanks to sour cream, while the crumb topping is thick, buttery, and loaded with sprinkles. And if you really want to take it over the top, a simple vanilla glaze ties everything together beautifully.

Whether you're serving this for brunch, dessert, or an afternoon snack with coffee, it's guaranteed to disappear fast.

What is Funfetti Crumb Cake? 

Think of your favorite crumb cake, but with all the nostalgic fun of a Funfetti cake.

You get:

• a soft vanilla cake base
• colorful rainbow sprinkles throughout
• a thick layer of buttery crumbs
• optional vanilla glaze

The result is part coffee cake, part birthday cake, and completely irresistible.

Funfetti Crumb Cake Ingredients

Unsalted Butter: Creates a rich, buttery cake base.

Granulated Sugar: Sweetens the cake while keeping the crumb light and tender.

Eggs: Provide structure and richness.

Vanilla Extract: The key flavor in any great funfetti cake.

Sour Cream: Keeps the cake incredibly moist and tender.

Milk: Adds moisture and helps create a smooth batter.

All-Purpose Flour: Gives the cake structure without making it heavy.

Baking Powder: Helps the cake rise beautifully.

Salt: Balances the sweetness.

Rainbow Sprinkles: Because more sprinkles is always a good idea.

How to Make Funfetti Crumb Cake

Step 1: Prepare the Pan

Preheat your oven to 350°F and line an 8x8-inch baking pan with parchment paper.

Step 2: Make the Crumb Topping

In a medium bowl, stir together:

• brown sugar
• granulated sugar
• flour
• cinnamon
• salt

Pour in the melted butter and mix until large crumbs form.

Fold in the rainbow sprinkles and set aside.

Step 3: Make the Cake Batter

In a large mixing bowl, cream the butter and sugar together until light and fluffy.

Add the eggs one at a time, followed by the vanilla extract.

Mix in the sour cream and milk until smooth.

Step 4: Add Dry Ingredients

Add the flour, baking powder, and salt. Mix just until combined. Fold in the rainbow sprinkles.

Step 5: Assemble

Spread the batter evenly into the prepared pan. Sprinkle a small handful of crumb topping over the batter first. Then add the remaining crumbs on top.

Use plenty. This is a crumb cake after all. Gently press the crumbs into the batter slightly so they stay in place while baking.

Step 6: Bake

Bake for 34–40 minutes, or until:

• the center is set
• a toothpick comes out mostly clean
• the crumb topping is lightly golden

Allow the cake to cool before slicing.

Tips for the Best Cake

• Use Jimmies Sprinkles - Jimmies work best because they hold their color during baking. Nonpareils can bleed into the batter.
• Don't Overmix Once you add the flour, mix only until combined. Overmixing can make the cake dense.
• Use Plenty of Crumb Topping- The thick crumb layer is what makes this recipe special. Don't be afraid to pile it on.
• Let It Cool - The crumb topping firms up as the cake cools, making it easier to slice.

How to Store Funfetti Crumb Cake

Room Temperature: Store covered for up to 3 days.

Refrigerator: Store for up to 5 days.

Freezer: Freeze individual slices for up to 2 months. Thaw overnight and enjoy at room temperature.

Frequently Asked Questions

Can I make this ahead of time?

Yes! In fact, the flavor is even better the next day.

What sprinkles work best?

Jimmies-style sprinkles hold their color best during baking.

Can I double the recipe?

Absolutely. Bake in a 9x13-inch pan and increase the bake time slightly.

Can I skip the glaze?

Of course. The cake is delicious with or without it.