I really think that my coworkers are trying to stump me when it comes to making them birthday treats. Pulling whatever kind of flavor they can out of their heads to see if I really can do it. I mean, we had gluten-free peanut butter & jelly cupcakes and gluten-free double chocolate peanut butter cupcakes this summer.
This time the request was for Boston Cream Pie Cupcakes – something that was actually a bit more traditional and a little less out there.
I decided that I was bored with the core & fill kind of cupcake, so I went a different route with these – I used a mini whoopie pie pan to make the cake pieces and then piped in some filling and poured on a thick glaze. And ended up with two-bite treats that were all gone before lunch.
The only caveat is that these do not transport well. If you try to take them on your 2-train 2-hour commute, they might just get a little banged up before you get them in to the office. (It won’t effect the flavor, but it might bruise your ego a wee bit). If these need to make a trip, I would bring all the components and assemble on-site. It takes about 10 minutes to combine all the parts into lovely little gluten-free boston cream (whoopie) pies.
- For the Cakes
- 175g (1¼ cups) gluten-free cake flour (143g high-quality all-purpose gluten-free flour + 4 tablespoons (32g) cornstarch)*
- ½ teaspoon xanthan gum (omit if your blend already contains it)
- ½ teaspoon baking powder
- ¼ teaspoon baking soda
- ¼ teaspoon kosher salt
- 109 grams (½ cup) packed light brown sugar
- 28 grams (2 tablespoons) unsalted butter, melted and cooled
- 24 grams (2 tablespoons) vegetable shortening, melted and cooled
- 1 extra-large egg at room temperature, beaten
- 1 teaspoon vanilla bean paste (or replace with equal volume pure vanilla extract)
- ½ cup + 2 tablespoons buttermilk
- For the pastry cream
- 30 grams (1/4 cup) cornstarch
- 150 grams (3/4 cup) sugar, divided
- 2 cups milk (I don’t drink milk, so I almost always use almond milk) , divided
- 4 egg yolks
- 1 teaspoon vanilla bean paste
- 2 tablespoons butter
- pinch of salt
- Chocolate Glaze
- 130 grams (4.5 ounces) bittersweet chocolate, roughly chopped
- 60 grams (4 tablespoons) butter
- 1 tablespoon corn syrup
- Preheat your oven to 325 degrees F and grease a mini whoopie pie pan.
- In a large bowl, place the flour, xanthan gum, baking powder, baking soda and salt and whisk to combine well.
- Whisk in the brown sugar, making sure you remove any lumps.
- Next, mix in the butter, shortening, egg and vanilla and make sure everything is well combined.
- Now, add the milk and vinegar, and mix again to combine well. You will have a batter that is somewhere between cake batter and cookie dough in consistency.
- Using a small scoop or you can pipe about as much as a large marble to each well of your whoopie pie pan.
- Bake on a center rack for 8-10 minutes, or until the cakes bounce back when pressed gently in the center. Remove from the oven and allow to cool in the pan for 10 minutes before transferring to a wire rack to cool completely. Repeat with the remaining batter.
- Prepare an ice bath.
- In a small mixing bowl, combine ¼ cup sugar, egg yolks and the creamer (or ½ cup milk).
- In a medium sauce pan over medium heat, bring the remaining 1½ cups milk to a boil, stirring constantly.
- Remove from heat and add the hot milk to the egg mixture about a third at a time to temper the eggs. If you do this too fast you will end up with scrambled egg yolks and not a smooth cream.
- Return the pot to the stove and add the egg mixture. Over medium heat, keep whisking until the cream thickens and when you scrape the bottom of a pot, the cream does not close the gap immediately. Stir in the vanilla, salt and butter.
- Put the pot over your ice bath and stir every 5-10 mintues for about half an hour, or until the cream has cooled.
- When you are ready to assemble the mini boston cream pies, melt together the chocolate, butter and corn syrup over low heat. If the mixture is not pourable, add an extra tablespoon of butter.
- Pipe the pastry cream onto half of the cake pieces. Take one of the other cake pieces and top each one. Pour or spread chocolate glaze on each mini Boston cream pie.
You’ve inspired me! The same idea struck me with the cupcakes, though instead what if the cupcakes were still made and once they were sufficiently cooled, they were cut in half? Much like making a layer cake, the tops were evened, the middle filled with the custard and then covered in chocolate?
I was considering cutting cupcakes in half, but thought I wouldn’t be able to handle it if I cut them imperfectly…
I am using your recipe for the pastry cream and am part-way in and realized that I don’t know where to use the cornstarch!!!!! I’m mixing with the eggs and sugar now…hopefully it works! Thanks for sharing your recipe!
Also – I just realized the sugar is divided too but not added in anywhere. I just tossed it in after tempering the eggs…it smells good, I’m sure it’ll turn out fine!