Mini Boston Cream Pie

Boston Cream Pie is a classic American dessert that epitomizes elegance and style.

The moist vanilla sponge and luscious pastry cream come together for an exceptional layer cake. When topped with decadent chocolate ganache, you know you're about to serve something extra special.

What you need

There are three elements to a Boston Cream Pie recipe: vanilla cake, pastry cream filling, and chocolate ganache topping.

This light and airy yellow cake recipe is Hot Milk and Butter Cake, so called because you use…uhm…hot milk and melted butter in the batter. It also contains flour, sugar, eggs, canola oil, baking powder, vanilla extract, and salt.

It's a richly flavored sponge, moist and tall.

Boston Cream filling is just pastry cream custard (aka crème pâtissière if you want to get fancy), essentially vanilla custard thickened with cornstarch. It's in the same family as ice cream, egg nog, bread pudding, and quiche.

The ingredients you need are milk, sugar, egg yolks, butter, and cornstarch. If you want an even richer pastry cream, you can substitute up to ½ cup of heavy cream for the milk.

It's best if you can use a fresh vanilla bean, but you can also use 1 teaspoon of vanilla extract instead.

Chocolate ganache is, well, fudgy chocolate nirvana. It can be used to glaze cakes (as it is here) or as the filling for tarts and truffles. 

This ganache is made from heavy cream and dark chocolate. Vanilla extract is added for extra richness, and the corn syrup helps to give the ganache stability and a beautiful sheen.

How to make Boston Cream Pie

Element 1: Hot Milk and Butter Cake

Step 1: Make the batter

Beat the sugar and eggs together at medium-high speed until lightened, about 3 to 4 minutes (batter will fall from the paddle in thick ribbons). Mix in the canola oil on low speed (photo 1).

Step 2: Heat the milk

Heat the milk and butter in a saucepan set over medium heat until small bubbles form and the mixture is steaming. Remove the pan from the heat and stir until the butter is fully melted. Stir in the vanilla extract (photo 3).

Step 3: Add the milk mixture to the batter

With the mixer going on low speed, slowly add the hot milk mixture to the cake batter, mixing until the batter is well combined. Scrape the bowl and mix briefly until the batter is smooth. It will be very thin (photo 4).

Step 4: Bake the cakes

Lightly spray two 6-inch round cake pans with baking spray, line with parchment paper, then spray the parchment. If you’re using Bake-Even strips (see the Pro Tip below), soak two in water for 5 minutes, wring them out, then wrap the pans with them tightly (you won't need to level the cakes later if you use them).

Divide the batter evenly into the prepared cake pans. You can do this by eye, or you can weight the batter with a kitchen scale (I measured about 290 grams). Place the cake pans on the scale and measure out half the weight of batter per pan (about 145 grams).

Bake the cakes at 325˚F for 25 to 30 minutes, or until they're a deep golden brown and beginning to pull away from the sides of the pan (photo 5). A cake tester inserted into the center should come out clean.

Remove the cakes from the oven and cool them in the pans for 10 minutes. Turn them out onto a rack to cool completely.

Element 2: Vanilla Bean Pastry Cream

You'll want to make the pastry cream while the cakes are in the oven to give it plenty of time to chill before assembly.

By the way, you can use this pastry cream recipe for vanilla pudding also - just reduce the cornstarch to two tablespoons. Alternatively, you can use this recipe for vanilla pudding without eggs or this no-egg chocolate pudding. Whichever method you choose, the pudding is guaranteed to be much better than anything you can get out of a box!

Step 5: Whisk the yolk mixture

Whisk the egg yolks briefly. Add half of the sugar and cornstarch and whisk to combine (photo 6). Set aside.

Step 6: Heat the milk mixture

This pastry cream is flavored with fresh vanilla bean seeds. Did I say vanilla bean seeds? No, flecks of flavor, more like! I don't always use a fresh vanilla bean in my baking, but I do when the vanilla will be showcased, like in Magic Custard Cake. 

Whisk together the milk and the remaining sugar in a medium saucepan. Using the tip of a sharp knife, split the vanilla bean and scrape the seeds into the milk mixture, then add the vanilla bean (photo 7).

You can always substitute one teaspoon of pure vanilla extract for the vanilla bean, if you wish. Just add it in with the butter after you've cooked the custard.

Step 7: Temper the egg mixture

Tempering eggs for custard isn't difficult, but what does tempering eggs mean?

Before you add the yolk mixture to the hot milk, it's important to gently warm the yolks first. This step helps avoid little pieces of cooked egg in your pastry cream. It's also helpful to start with room-temperature egg yolks.

Heat the milk mixture over medium heat, stirring occasionally, until small bubbles form and it starts to steam.

Gently heat the egg mixture by slowly adding ¼ cup of the warmed milk mixture to the yolk mixture while continuously whisking. Add another ¼ cup of the milk and whisk the yolk mixture again. When the eggs feel warm to the touch, you can add the yolk mixture to the pan (photo 8). This process is called tempering the eggs.

Step 8: Cook the pastry cream

Cook the custard, whisking constantly, until the pastry cream is bubbling and thickened. Allow it to boil approximately 1 minute longer, stirring constantly. Don't overcook the pastry cream to avoid overcooking the eggs. Remove the pastry cream from the heat (photo 9).

Step 9: Strain and chill the pastry cream

Strain the custard through a fine mesh strainer into a clean bowl, removing the spent vanilla bean. If the custard boiled during thickening, straining it out will help remove any curdled bits of egg.

Don’t toss that vanilla bean - instead rinse the bean, then place it in a jar and cover with vodka to make your own vanilla extract. If you are using vanilla extract instead of a vanilla bean, stir it in now.

Add the butter and stir until it melts, but don't over-mix, as this will thin the custard (photo 10).

Element 3: Chocolate Ganache

Chocolate ganache is made with equal parts chocolate and heavy cream, by weight. A kitchen scale is helpful here.

While dark chocolate provides the most contrast to the sweet cake and pastry cream, you can choose your chocolate type - milk, semi sweet, or dark - depending on your preference. Just make sure it's good quality. Hint: chop the chocolate with a serrated knife - it cuts it cleaner than a chef's knife.

Step 10: Add heated cream to chopped chocolate

Place the chopped chocolate in a heat-proof bowl. Heat the cream to a simmer, either on the stove in a small saucepan or in the microwave.

Pour the cream onto the chocolate, cover, and let sit for 2 to 3 minutes, then start stirring. At first it will look grainy, but keep stirring until the mixture is smooth.

Add the corn syrup (if using) and vanilla and stir well (photo 12).

Step 11: Assemble the Boston Cream Pie

Level the cakes (if needed). Place one of the cakes, right side up, on a cake plate. Top with the pastry cream, spreading it right to the edges (you want at least ½-inch of filling inside when the cake is assembled).

Place the top layer, upside down, on the filling (photo 13).

Questions asked and answered

Here are some questions you might have...

Pro Tip: Bake flat topped cakes

One trick to ensure the cake layers will be even is to use damp Bake-Even strips wrapped snugly around a cake pan. They insulate the outside part of the cake pan, allowing the center of the batter to bake…well…evenly with the outer edges. What you get is a flat-topped layer cake that then doesn’t have to be trimmed.

Check out this Port Wine Chocolate Cake recipe to see the Bake-Even strips in action. No leveling needed! Here's one of the layers before and after baking. See how even it looks? There's no cracked dome on top.

One elegant dessert

Boston Cream Pie is one of those desserts that take a little time and patience to make, but the result is so incredible that it’s well worth the effort.

The hot milk and butter cake is moist and light, and complemented by the rich vanilla bean pastry cream. The dark chocolate ganache adds a luxurious counterpoint that tempers the sweetness while adding body to the cake.

This 6-inch Boston Cream Pie recipe is sized for a small group. For a full-sized cake, just double all the ingredients, and bake the cake layers in two 9-inch round cake pans.

If you're celebrating a birthday, Valentine's Day, Christmas, New Year's Eve, or any other special moment, this is truly an elegant dessert to share with a special person or people in your life.

It’ll make any day exceptional!

Slainté! L’chaim! Cheers!

Tammy