Fluffy vanilla cupcakes filled with Boston cream and topped off with a silky chocolate ganache. Made completely from scratch, this Boston Cream Cupcake recipe yields 24 cupcakes but can be cut in half. Includes a step-by-step video!
If you’ve ever had a slice of Boston cream pie before, you already know that it’s not actually a pie, at least not in the traditional sense. Rather than being neatly served in a pie crust, Boston cream pie is actually a vanilla cake filled with custard and topped with silky chocolate ganache.
Since we’ve already broken with classic pie convention, I see no harm in taking things a step further and serving in cupcake form, instead. Boston cream cupcakes are even more delicious than the faux-pie, anyway, if you ask me, because our ratios of cream, cupcake, and chocolate are perfectly proportioned and you get just the right amount of each in every bite.
Today’s recipe is a bit more involved than some of my other cupcake recipes so to make it worth your while it yields 24 cupcakes, though you could certainly cut the recipe in half if needed (or if you don’t happen to have 9 eggs lying around!).
Real Boston Cream (Not Pudding)
Many Boston cream cupcake recipes take some liberties with the Boston cream filling and use instant vanilla pudding instead. I get it, honestly, because making Boston cream (pastry cream) is a bit more time consuming and there’s some more technique involved. However, I think the effort is completely worth it so I’m including my pastry cream recipe in today’s post. This is definitely a recipe worth learning, I’ve used it frequently on the blog, and once you master it you’re halfway on your way to making perfect homemade cream puffs or flawless French Eclairs!
If you’ve never made Boston cream before, make sure to watch how I make it in the video before beginning. Since the cream will need to cool for several hours before it is usable, I recommend making it first (or you can make it up to 3 days in advance of making/assembling the cupcakes).
Filling Boston Cream Cupcakes
Some people use fancy cupcake corers to fill their cupcakes, but I’ve never owned one and have found that a knife works just fine.
First let the cupcakes cool completely. Use a sharp knife to carefully carve a hole that’s 1 ½″ wide at the top and slightly narrows a bit until you’ve made a 1″ deep cavity into the cupcake. Remove this core and slice off the bottom, reserving about a ¼″ deep layer of the surface. This will be your plug once you fill your cupcakes (see photo below). You might recognize this carving technique from my gender reveal cupcakes or pinata cupcakes, and in fact it can be used to fill just about any cupcake recipe, with just about anything.
Then, fill your cupcakes with chilled pastry cream. You can fit a piping bag with a simple round tip or just snip the corner off of a ziploc bag (or, really, just use a spoon to dollop in the frosting, but it won’t fill it as compactly). Fill the cupcake almost to the brim, then cap the cream with your reserved cupcake plug.
No Boston cream cupcake would be complete without a shiny, silky layer of chocolate ganache. I make mine in the microwave, heating together chocolate, cream, and corn syrup until melted and then stirring in a bit of powdered sugar.
The corn syrup that is used here is not the same thing as high fructose corn syrup (and I’ve used it in some of my most popular recipes, like my favorite sugar cookie icing), but if you don’t want to use it or don’t have it in your pantry, just leave it out. Your ganache just won’t be quite as glossy or thick.
Immediately after melting your ganache it will be a bit too thin to pour over your cupcakes without making a mess and running right off the top. Let it thicken for at least 10-15 minutes or so before spooning (generously!) over the surface of each cupcake.
If you want to try a more traditional type of frosting, I recommend my favorite chocolate frosting instead.
How to Store
Store in the refrigerator in an airtight container, they’ll keep for 4-5 days this way. Because of the cream filling, I recommend keeping Boston cream cupcakes at room temperature for no longer than a few hours. I don’t recommend freezing this recipe as the pastry cream may break down in the freezer.
More Fun Recipes to Try:
Let’s bake together! Be sure to check out my video in the recipe where I’ll show you exactly how I make these in my own kitchen!
Boston Cream Cupcakes
- ½ cup (113 g) unsalted butter softened
- ½ cup (118 ml) canola oil or vegetable oil or other neutral oil
- 1 ¾ cups (350 g) granulated sugar
- 4 large eggs
- 2 teaspoons vanilla extract
- 3 cups (375 g) all-purpose flour
- 1 Tablespoon baking powder
- ¾ teaspoon salt
- 1 ¼ cups (300 ml) buttermilk room temperature preferred
- 1 cup (170 g) semisweet chocolate chips
- ½ cup (118 ml) heavy cream
- 2 Tablespoons light corn syrup³
- ⅓ cup (45 g) powdered sugar icing sugar
- Combine milk, cream, ⅓ cup sugar, and salt in a medium-sized saucepan over medium heat. Stir frequently until sugar is dissolved and mixture begins to simmer. Remove from heat and allow to cool for 10 minutes.1 cup (236 ml) milk¹, 1 cup (236 ml) heavy cream¹, ⅓ cup (67 g) + 3 Tablespoons granulated sugar, ¼ teaspoon salt
- In a separate large bowl, vigorously whisk together egg yolks and remaining sugar until sugar begins to dissolve (about 15-30 seconds). Sprinkle cornstarch over mixture and whisk until combined and slightly thickened.5 large egg yolks², 3 Tablespoons cornstarch
- While whisking constantly, slowly drizzle about ⅓ cup of milk mixture into the egg mixture (we’re tempering the mixture this way to keep the eggs from cooking). Gradually add remaining cream until completely combined.
- Pour mixture back into saucepan and return to the stovetop over medium heat, whisking frequently until mixture begins to thicken. Remove from heat and pour through a fine mesh strainer into a heatproof bowl. Add vanilla and whisk in butter, one piece at a time, until completely melted and mixture is smooth.1 teaspoon vanilla extract, 4 Tablespoons unsalted butter
- Place a piece of plastic wrap directly against the surface of the pastry cream, allow to cool at room temperature for 20 minutes then transfer to refrigerator to chill completely (about 2 hours). Meanwhile, prepare cupcakes.
- Preheat oven to 350F (175C) and line two 12-count cupcake tins with paper liners. Set aside.
- With an electric or stand mixer, beat together butter, oil, and sugar until light, fluffy, and well-combined (about 30 seconds on medium/high speed)½ cup (113 g) unsalted butter, ½ cup (118 ml) canola oil, 1 ¾ cups (350 g) granulated sugar
- Add eggs, one at a time, stirring well after each addition, and stir in vanilla extract.4 large eggs, 2 teaspoons vanilla extract
- In a separate bowl whisk together flour, baking powder, and salt.3 cups (375 g) all-purpose flour, 1 Tablespoon baking powder, ¾ teaspoon salt
- Using a spatula now rather than the electric mixer, gradually alternate adding the flour mixture and buttermilk to the butter/oil batter, starting and ending with the flour mixture and stirring until just-combined after each addition. Ingredients should be thoroughly combined, but take care not to over-mix or your cupcakes will be dense and dry.1 ¼ cups (300 ml) buttermilk
- Fill cupcake liners no more than ¾ full (if you have extra batter discard it, don’t overfill the liners or your cupcakes will cave in), transfer to center rack of oven (I usually bake one pan at a time to ensure even baking), and bake for 17-19 minutes or until a toothpick inserted in the center comes out clean or with a few moist crumbs. Allow to cool for 10 minutes in cupcake pan then transfer to wire rack to cool completely.
- Shortly before you’re ready to assemble, prepare chocolate frosting by combining chocolate chips, heavy cream, and corn syrup in a large heatproof bowl. Heat in the microwave in 25 second increments, stirring well in between, until chocolate is completely melted and mixture is smooth. Sift in powdered sugar and allow to cool for about 10 minutes (you can carve and fill your cupcakes during this time) or until ganache is still fluid but not so runny that it will run right off the cupcakes.1 cup (170 g) semisweet chocolate chips, ½ cup (118 ml) heavy cream, 2 Tablespoons light corn syrup³, ⅓ cup (45 g) powdered sugar
- Once cupcakes are cooled and pastry cream is chilled, fill a large piping bag fitted with a round tip (or use a ziploc bag with a corner cut off) with pastry cream. Use a knife to cut a 1 ½ ” wide and 1” deep cavity into each cupcake (don’t cut all the way to the bottom!). Remove this core from your cupcake and then slice off the bottom so only a ¼” thick piece of the surface remains (see pictures in post or video for a visual).
- Fill cupcake with pastry cream and top with reserved ¼” thick cupcake surface, fitting it snugly against the pastry cream. Drizzle ganache generously over the top of each cupcake, then allow ganache to harden before serving.
- Store cupcakes in the refrigerator in an airtight container for up to 5 days.
Nutritional information is based on third-party calculations and should be considered an estimate only. Actual nutritional content will vary based upon brands used, measuring methods, cooking method, portion sizes, and more.