There is something so wonderful about a 9×13 cake! They’re approachable, work well for serving a crowd, you don’t have to fuss with stacking layers, and oftentimes they’re so unassuming that their flavor will catch you by surprise. Case in point — Bea’s Blueberry Sheet Cake. The color of that frosting will pique anyone’s interest right away, it’s true, but once you’re one bite into a slice, you kind of forget about all other cakes before it. Full of bright lemon, fresh blueberry flavor, and a blueberry-cream cheese frosting that’ll make you want to quit all others, this simple sheet cake is one you’ll keep coming back to again and again.

What Ingredients Do You Need for Bea’s Blueberry Sheet Cake?

Two lists — one for the cake, one for the frosting — and every ingredient earns its place. For the cake you’ll need:

• All-purpose flour.
• Baking powder and baking soda. Some salt.
• Butter.
• Granulated sugar.
• Eggs.
• Vanilla extract.
• Buttermilk. (The secret to an incredibly tender, moist crumb!)
• Lemon zest and lemon juice. (Three lemons’ worth of zest — don’t hold back!)
• And fresh blueberries!

For the frosting you’ll need:

• More butter.
• Cream cheese.
• Blueberry jam. (This is what gives the frosting its gorgeous color and fruity flavor!)
• Powdered sugar.
• And vanilla extract.

Why toss the blueberries in flour first?
It’s a simple but important trick! Coating the blueberries in a little flour before folding them into the batter helps keep them suspended throughout the cake rather than sinking to the bottom during baking. It takes about ten seconds and makes a real difference in having blueberry flavor throughout every slice.

How Do You Make Bea’s Blueberry Sheet Cake?

This is a straightforward sheet cake that requires only a little patience, mainly when it comes to letting the cake cool completely before frosting. Rush that step and you’ll have melty frosting sliding off the sides, and no one wants that! That frosting is too good to waste.

Here’s how you make it:

Cream the butter and sugar together until they’re light and fluffy. Creaming butter and sugar takes a couple of minutes to do it right, so don’t rush it. Then add the eggs, vanilla, and buttermilk and mix to combine. Add the dry ingredients in two additions (to avoid making a mess), then stir in the lemon juice and all that glorious zest.

Toss the blueberries in a tablespoon of flour and fold them gently into the batter so they’re evenly distributed but don’t sink to the bottom. Pour that batter into a greased 9×13 pan and get it in the oven!

While the cake cools, make the frosting. You want to start by whipping the butter until it’s pale and fluffy, and then beating in the cream cheese and blueberry jam until they’re smooth. Add the powdered sugar a little at a time, then whip it all together on high until the frosting is light, airy, and a beautiful shade of purple that will make everyone stop and stare. (If you’re not totally happy with it you can up the ante with food coloring.) Spread it generously over the cake, slice, and serve. Try to have patience when fending off requests for the recipe!