Boston Cream Pie

This classic cake combines three simple components to make one fabulous dessert; moist delicate vanilla cake filled with silky vanilla pastry cream and topped by a decadent chocolate ganache. If you’re confused as to why this “pie” looks like a cake, you’re not alone, cakes used to be baked in pie tins! 

What You’ll Need for This Recipe

Vanilla: You can use a vanilla extract or if you want to see the little specks in your pastry cream use vanilla bean paste or a vanilla bean.

Cream: You can make the ganache with JUST chocolate and whipping cream but adding a tablespoon or two of light corn syrup will make it super-shiny and smooth.

Eggs: Large eggs are preferable and always make sure they are room temperature.

How to Make Boston Cream Pie

1. Start off by making the pastry cream. Scald the milk in a medium-sized heavy-bottomed pot then set aside. In a large bowl whisk the egg yolks and sugar until light in color and thicker in consistency. Sift in the corn starch and whisk until smooth and fully incorporated and drizzle in about 1/4 cup of the hot milk while whisking vigorously then pour in the remaining milk and whisk to combine. 

2. Strain the mixture back into the pot and place over medium high heat whisking continuously until thickened. Once thickened cook an additional minute while whisking then remove rom heat and stir in the butter. Transfer the custard to a bowl and allow to cool for a few minutes then press plastic onto the surface and chill. We want the custard to cool and thicken up before spreading it onto the cake so make it first and test the consistency before spreading onto the cake.

3. Now it’s time for the cake. Preheat your oven to 350F and prep an eight inch cake pan. Butter the side and bottom then press a round piece of parchment paper into the bottom. Add a few teaspoons of flour and kick them around to coat the side. I always use cake strips when baking, if you use them place one in some water to soak. Stir the flour, salt, and baking powder together in a bowl and set aside.

Add the milk and butter to a microwave safe cup or bowl and heat in 30 second bursts stirring in between until the butter is melted and the milk is steaming, about 160F, then set aside. Beat the eggs and sugar on medium speed for about 4 minutes. You’ll see the mixture thicken up and the whisk will leave trails in it’s wake.

4. Add the flour and mix on low until just combined then slowly pour in the milk and mix until combined. Scrape the bowl down and mix a few seconds more to make sure you have a homogenous mixture. Pour the batter into your prepared cake pan, add baking strip if using and bake at 350F for about 33 minutes or until the center is springy to the touch and a skewer inserted in the middle comes out clean. Allow to cool in pan for a few minutes then invert onto a wire rack, remove paper and allow to cool fully.

5. Once the cake has cooled use a sharp serrated knife and cut in half. Add the cooled and thickened pastry cream to the first layer then smooth out toward the edge leaving about an inch at the edge uncovered. Add the second layer on top then cover with plastic and place in refrigerator to chill for 2 hours to overnight. If you made the pastry cream a day ahead you may need to give it a quick whip to loosen it up.

6. Make the ganache. Once your cake has set add the heavy cream to a microwave safe bowl and heat for about a minute or until steamy. You can definitely mix in a tablespoon of corn syrup with the cream before heating, this will give you a very glossy ganache. Add the chopped chocolate into the steamy cream and let it sit for five minutes then gently stir until smooth. Pour ganache onto the cake and smooth to the edge.

Pro Tips for this Recipe

• Measure your flour correctly! Adding too much flour to the recipe is the most common mistake. The best, and easiest way to measure flour is by using a scale. If you don’t have one then fluff your flour with a spoon, sprinkle it into your measuring cup, and use a knife to level it off.
• Use a serrated knife to cut the cake in half. If you’re worried about cutting it evenly, place toothpicks a few inches apart around the equator. Use them as a guide for your knife. It’s also okay if it’s not perfect! It will taste great either way.
• Use room temperature eggs for the pastry cream and sponge cake. This will help the cream cook faster and the cake to whip up better for a fluffier texture.
• Try using Hersey’s Special Dark chocolate bars for the ganache because it gives a deep dark chocolate color and shiny texture. If you’ve got bittersweet chocolate chips or baking bars in your cabinet, those will work great too! Add a tablespoon of corn syrup to the ganache for a shiny finish.
• Slice finished cake with a warm, non-serrated knife for clean cuts.
• Cook the pastry cream for a minute or two while whisking to help thicken it.
• Unlike more traditional sponge cakes that call for folding in whipped egg whites, this version uses what is referred to as a hot-milk method. It’s more fool-proof when baking and results in a very flavorful cake.  

Frequently Asked Questions

Why is it called Boston cream pie?

If you’re confused as to why this cake is called a pie, you’re not alone. The recipe originated back in the mid 1800s when cakes were often baked in pie tins because they were very common kitchen items. It is indeed a cake filled with a tempting vanilla bean-speckled pastry cream.

What is Boston cream filling made of?

This delicious cake is filled with pastry cream or creme patissiere in French. It’s a silky custard made from egg yolks and sugar most often flavored with vanilla.

Should you refrigerate it?

You should DEFINITELY refrigerate Boston Cream Pie. The pastry cream is highly perishable and will go bad if left out at room temperature for more than an hour or two and it will soften and not be able to support the heavy ganache on top especially after you’ve started cutting into it. 

If you’ve tried this Boston Cream Pie recipe then don’t forget to leave a rating and let me know how you got on in the comments below, I love hearing from you!