Boston Cream Pie Cupcakes
In 1996 Boston Cream Pie was declared the official dessert of Massachusetts. Huh. Thanks, Wikipedia. You learn something new every day. Also, it’s not mass-produced in Boston.
I guess because I’m a total weirdo I’ve probably only had one or two Boston Cream Pies in my day. Even when I briefly lived in Boston I don’t recall ever having Boston Cream Pie. I think I once had Boston Cream Pie at my grandparent’s house. My grandfather got terribly lost in Boston once and held a bit of a grudge. He insisted on calling it Massachusetts Cream Pie.
In January I made my first Boston Cream Pie and I was pretty pleased with it. I thought the cake to filling ratio was a bit off though. It could have used more custard, and probably some more chocolate topping. But I like chocolate and custard and really I think most desserts need more custard and chocolate.
A few months ago I made yellow cupcakes filled with lemon curd and topped with a whipped mascarpone topping. While the notion of filled cupcakes wasn’t new to me, I had never made them myself and I began to think of all of the different things I could fill cupcakes with. While there’s a pretty long list of filled cupcakes, the first one on my list was Boston Cream Pie cupcakes. Seeing as I volunteered to make cupcakes for a birthday I decided I’d give Boston Cream Pie cupcakes a shot. And I have to say they were pretty tasty.
Yellow Cake Cupcakes
From Smitten Kitchen
The first time I used this recipe (in layer cake form) I noticed the batter rose a lot while baking. To make sure they didn’t overflow in cupcake form, I erred on the side of caution and filled my tins up about 2/3 of the way instead of 3/4 of the way. While it made for 30 cupcakes, they were all a consistent, perfect size, and a few extra cupcakes never hurt anyone.
- 4 cups plus 2 tablespoons cake flour
- 2 teaspoons baking powder
- 1 1/2 teaspoons baking soda
- 1 teaspoon salt
- 2 sticks (1 cup or 1/2 pound) unsalted butter, softened
- 2 cups sugar
- 2 teaspoons pure vanilla extract
- 4 large eggs, at room temperature
- 2 cups buttermilk, well-shaken
Preheat oven to 350°F. Line 2 12-capacity muffin tins with paper liners (or butter and flour two 9-inch round cake pans and line with circles of parchment paper, then butter and flour parchment).
Sift together flour, baking powder, baking soda, and salt in a medium bowl.
Using a stand mixer with the paddle attachment, beat butter and sugar at medium speed until pale and fluffy, about 5 minutes. I’m a strong believer that you cannot over-mix butter and sugar. The fluffier and lighter the better. Beat in vanilla. Add eggs 1 at a time, beating until incorporated and scraping down the bowl after each addition. At low speed, beat in buttermilk until just combined (mixture will look curdled). Add flour mixture in three batches, mixing until each addition is just incorporated. Scrape down bowl.
Fill muffin tins 2/3 of the way full and bake for 18-22 minutes. I always test my cupcakes at 18 minutes and then bake for longer, if necessary, checking again a minute or two later. For the longest time I used to believe a cake tester should come out clean; however, a better judge of doneness is if a few moist crumbs stick to your cake tester.
Since I could only bake 24 cupcakes at a time, I put the extra batter in the fridge while the first batch was baking. I found the refrigerated batter needed an extra minute more.
If baking in layer cake form, divide batter and spread evenly between the two cake pans. Bake until golden, approximately 35 to 40 minutes. Cool in pan on a rack for 10 minutes before removing from pan and cooling completely.
Vanilla Custard Filling
Adapted from AllRecipes.com
- 1 cup light cream
- 1 cup milk, divided
- 1/2 cup white sugar
- ½ teaspoon salt
- 8 teaspoons cornstarch
- 4 eggs
- 1 and 1/2 teaspoons vanilla extract
Combine cream with 1/2 cup of the milk and cook over medium heat until bubbles begin to form around the edge of the pan. Immediately add 1/4 cup of the sugar and the salt, stirring until dissolved. Remove the pan from the heat.
In a small bowl, combine the remaining 1/2 cup of the milk with the cornstarch and whisk to remove lumps. Whisk in the eggs. Add the hot cream mixture in a thin stream, whisking constantly. Return mixture to the saucepan and cook over medium-low heat, stirring constantly, until the custard thickens and is smooth (about 5 minutes). Remove from heat and stir in the vanilla. If you’re super meticulous you can strain your custard. This ensures there are no eggy bits or lumps, but so long as you constantly stir while cooking, it should be smooth and you can be lazy and not strain. Yay! Place a layer of syran wrap dirrectly on the surface of the custard. This ensures a film or skin doesn’t develop. Let cool completely.
This can be made one or two days in advance and stored in the fridge. It gets really gloopy and thick when it’s completely chilled. I thought I had messed up somewhere along the way the first time I made it, but it gets a silky smooth texture after bringing back to room temperature and whisking.
Instant Fudge Frosting
Adapted from Smitten Kitchen
A Boston Cream Pie typically has more of a glaze or ganache, but since I was making cupcakes I decided a rich, chocolatey frosting would look nicer.
- 6 ounces unsweetened chocolate, melted and cooled
- 4 cups confectioners’ sugar (no need to sift)
- 3 sticks (12 ounces) unsalted butter, at room temperature
- 6 tablespoons half-and-half or whole milk
- 1 tablespoon vanilla extract (yes, that’s tablespoon. It may seem like a lot, but it’s the perfect amount)
- 1 teaspoon instant coffee
- ½ teaspoon salt
In a stand mixer with the paddle attachment, beat together all ingredients besides chocolate until light and fluffy, about 3-5 minutes. Gradually add in the chocolate. You want to ensure the chocolate has sufficiently cooled, as hot chocolate will melt the butter.
To assemble cupcakes:
After cupcakes have cooled completely, you’ll want to create a well to add the custard filling. There are cupcake corers that I’m sure work nicely but I don’t have one. I found using a melon baller worked nicely (but simply creating a slit with a knife also works).
You can fill the cupcakes in a variety of ways, but I find using a disposable pastry bag with the tip cut off (or using a small pastry tip) is the fastest. I think I filled my cupcakes in roughly 45 seconds. Fast and easy.
They won’t look very pretty at this stage, but that’s okay. You still need to frost them. Also, please ignore how unevenly brown the cupcakes are. Oops.
From there, frost as you would any cupcake. I like the look of using a pastry bag to pipe on the frosting, but a just spreading on with a knife works perfectly as well.