Easy Boston Cream Pie Recipe (Using Cake Mix)

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This easy Boston Cream Pie recipe uses a simple cake mix with a quick technique that still gives it that classic sponge cake texture. It's filled with a luscious, easy-to-make cream filling and topped with rich chocolate ganache.

A layered cake on a cake stand, with cream filling and chocolate ganache dripping down the sides.

You'll love how simple this Boston Cream Pie is to make, yet it tastes like it came from a fancy bakery!

The recipe starts with a standard vanilla cake mix and other basic ingredients you likely already have in your kitchen. But here's the secret: whipping the egg whites separately and sifting the cake mix gives the cake an incredibly light and airy texture, just like a classic sponge cake.

When it comes to the custard filling, I've got the easiest pastry cream recipe for you. Unlike most pastry cream recipes, you don't need to temper your eggs, resulting in a smooth, creamy filling.

A fudgy chocolate ganache tops this dreamy cake. Your family and friends will be so impressed!

Key Ingredients and Substitutions

Looking for the full recipe? The recipe card at the bottom of this post includes the complete list of ingredients, measurements, and instructions.

Cake Mix - Use your favorite cake mix and the ingredient amounts listed on the box. The measurements in the recipe card are based on a Betty Crocker Vanilla Cake mix.

Eggs - This recipe uses 7 eggs total. Keep them cold until you are ready to separate the whites from the yolks.

Half and Half - If you do not have half and half, you can make your own by mixing 1 ½ cups of whole milk with ½ cup of heavy cream.

Baking Chocolate - Use bittersweet baking squares for the smoothest consistency. Chocolate chips will also work, but the texture will be a little different due to the stabilizers used in chocolate chips and the amount of cocoa butter.

Heavy Cream - The higher your cream's fat content, the more stable your ganache will be.

Corn Syrup - Light corn syrup is what makes the ganache glossy. You can substitute honey or leave it out entirely if you prefer.

How to Make Boston Cream Pie

1) Prepare Pastry Cream

Combine the egg yolk, sugar, and cornstarch. The mixture will resemble cooked egg yolk.
Add the mixture and the half and half to a saucepan and cook on medium-low heat for 5 minutes. Raise the temperature and let it boil for one minute.
Whisk continuously across the bottom and sides of the pan so that the custard does not burn.
Remove the pan from the stove and whisk in the butter and vanilla. The custard should be nice and thick and will continue to thicken as it cools.
Transfer the vanilla custard to a clean bowl. Press a piece of plastic wrap directly against the custard's surface. This prevents a film from forming on top of the custard.
Refrigerate for at least 2 hours or up to 2 days.

4 images showing eggs and cornstarch mixed together, heavy cream added in pan, custard with butter and vanilla on top, and pastry cream in a bowl.

2) Bake Cake Layers

This recipe uses cake mix to easily make a buttery sponge cake. These Baked Alaska and Black Forest Cupcakes also use cake mix as a shortcut!
Sift the cake mix to make a lighter batter.
Beat the egg whites on high speed with a whisk attachment until they form stiff peaks.
Put all the cake ingredients, except for the egg whites, into a large mixing bowl and beat for two minutes.
Gently fold the egg whites into the batter by scooping the spatula under it, then turning it over onto the egg whites. Do this softly so that you keep the texture of the egg whites.
You will end up with pockets of egg whites distributed throughout the batter.
Pour the batter into two 9-inch pans and bake according to the directions on the box, then cool completely.

4 images showing whipped egg whites, sifting cake mix, and folding the whites into the cake batter.

3) Make Ganache

Place the cream, corn syrup, and chocolate in a saucepan over medium heat. Stir continuously until the chocolate is melted.
Remove the pan from heat and stir in the vanilla.
Let cool for about 10 minutes while you assemble the cake.

2 images showing ganache ingredients in a pan and then melted together.

4) Assemble the Cake

Place one layer of the cake onto a cake plate or serving platter.
Spoon the custard filling over the top of the cake to the ends.
Place the second layer on top of the vanilla cream.
Pour the chocolate ganache over the top, letting it spill down the sides of the cake.

Expert Tips

Eggs separate best when they are cold, but egg whites whip more fully when they are at room temperature. Separate all of the eggs about 30 minutes before you begin making the recipe.
To test if the egg whites are stiff, use a spoon or the whisk attachment to scoop into the egg whites and pull up. It is ready if it will leave a crevice and a tall peak. If the peak starts to droop, beat it some more.
If you skip sifting the cake mix, you'll still have a great cake, but this extra step makes it more like a traditional sponge cake.
Let the chocolate cool until it has the texture of heavy cream.

Storage Guidelines

Because of the custard filling, Boston Cream Pie needs to be refrigerated. Wrap in plastic wrap and store in the refrigerator for up to 5 days.

You can make the custard and filling up to 2 days in advance, but wait to make the ganache until you are ready to assemble the dessert. If you want the entire cake made and assembled in advance, you can do that up to 24 hours ahead.

Slice of boston cream pie on it's side, another slice and the cake stand in the background.

Recipe FAQs

What if my pastry cream has lumps?

Some small lumps in the custard will not be noticeable in the finished cake. To achieve a completely smooth custard, strain it using a fine-mesh sieve.

Why is it called pie if it's a cake?

When Boston Cream Pie was invented in the mid-1800s, pie plates were the most common cooking vessel. People even baked cakes in pie plates! Because of this, cake was sometimes called pie.

Let me know how you like this recipe by leaving a review! And follow along on Instagram @stateofdinner for behind-the-scenes and to be among the first to know when new recipes post!

Recipe

This recipe was originally published on October 20, 2020. It was updated on April 25, 2024 with new photos, additional information, and clarified instructions.

Key Ingredients and Substitutions