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This classic Boston Cream Cake is two delicious layers of fluffy vanilla cake sandwiched over a layer of silky vanilla pastry cream and topped with rich and perfect chocolate ganache.
Serve this decadent dessert after a meal of Roasted Chicken Thighs with Carrots and Potatoes or enjoy another classic sandwich-style dessert recipe of Oatmeal Cream Pies.
This cake is sweet, rich, and decadent. It is a classic cake recipe that is made up of three different components. The soft and fluffy yellow cake, the thick and velvety sweet pastry cream, and a rich chocolate ganache topping. To keep this recipe super simple, use your favorite box of yellow cake mix and follow the instructions on the box.
Ingredient Notes
- Egg yolks - Save the egg whites for another recipe, the yolks make the cream thick and creamy. Allow them to come to room temperature before using for best results.
- Cornstarch - Helps to thicken the cream.
- All-purpose flour - This ingredient will also help to thicken the pastry cream and help it to set.
- Granulated sugar - Adds sweetness to the pastry cream.
- Butter - Bring to room temperature and add a creaminess to the filling.
- Heavy cream - Use to make the cream and the ganache.
- Whole milk - Give the pastry cream movement. Be sure to use whole milk and no substitute.
- Vanilla extract - Pure vanilla extract!
- Salt - Just a pinch, may omit if using salted butter.
- Yellow cake mix - Follow the ingredients and instructions on the box to make the fluffly cake part of the recipe, the simple way.
- Dark chocolate - The rich and decadent part of the ganache.
Instructions
Begin the recipe by making the pastry cream in a large bowl, whisk together the egg yolks, cornstarch, all-purpose flour, and granulated sugar, until combined. Set aside.
In a medium saucepan over medium heat, add in the butter and allow it to melt. Add in the heavy cream, milk, vanilla extract, and a pinch of salt. Stir and allow the mixture to come to a low boil.
Adjust the heat to low and very slowly pour and whisk the egg yolk mixture into the milk mixture until it becomes bubbly and begins to slightly thicken, about 1 to 2 minutes. Carefully remove the saucepan from the heat and pour it through a fine-mesh strainer into a large glass mixing bowl. Discard any chunks left in the strainer.
Place a piece of plastic wrap over the bowl, allowing it to touch the top of the pastry cream. Place the bowl in the refrigerator and allow it to chill and set/completely thicken for about 3 to 4 hours. *Stir before spreading on the cake.
Make the cake according to the yellow cake mix package instructions. Be sure to follow the instructions on the box to make 2 round layers.
Once finished carefully remove the cake pans from the oven and allow them to cool on a rack for about 10 minutes before removing the cakes from the pans to finish cooling completely on a rack.
Begin assembling the cake by adding one layer to a serving cake plate and topping it with an even layer of pastry cream filling. Leave a small amount (about ⅛-inch) empty around the edge of the cake. Add the second cake layer on top and gently press the top of the cake to allow the pastry cream to fill in the middle.
In a saucepan over medium-low heat, add the heavy cream and allow it to heat for 1 to 2 minutes before adding the dark chocolate. Stir until melted and smooth. Remove the saucepan from the heat and allow it to sit undisturbed for 2 to 3 minutes.
Whisk the ganache, and pour on top of the cake, spreading it to the edges so that it drips on the sides of the cake. Allow it to sit for 10 minutes before slicing to serve. Enjoy!
Storage
Store any unfinished Boston cream cake in an airtight container in the refrigerator for up to 4 days. Pastry cream is highly perishable, so try your best not to leave this cake out at room temperature for 1 to 2 hours.
📖 Recipe
Boston Cream Cake
Ingredients
- Pastry Cream Filling:
- 5 large egg yolks
- 2 tablespoons cornstarch
- 2 tablespoons all-purpose flour
- ¼ cup granulated sugar
- 4 tablespoons butter
- 1 cup heavy cream
- 1 cup whole milk
- 1 ½ teaspoons vanilla extract
- pinch of salt
- Cake:
- 1 box yellow cake mix (plus ingredients, bake according to package instructions)
- Chocolate Ganache:
- ½ cup heavy cream
- 4 ounces dark chocolate, chopped
Instructions
- Make the pastry cream in a large bowl, whisk together the 5 large egg yolks, 2 tablespoons cornstarch, 2 tablespoons all-purpose flour, and ¼ cup granulated sugar, until combined. Set aside.
- In a medium saucepan over medium heat, add in the 4 tablespoons butter and allow it to melt. Add in the 1 cup heavy cream, 1 cup milk, 1 ½ teaspoons vanilla extract, and a pinch of salt. Stir and allow the mixture to come to a low boil.
- Adjust the heat to low and very slowly pour and whisk the egg yolk mixture into the milk mixture until it becomes bubbly and begins to slightly thicken, about 1 to 2 minutes.
- Carefully remove the saucepan from the heat and pour it through a fine-mesh strainer into a large glass mixing bowl. Discard any chunks left in the strainer. Place a piece of plastic wrap over the bowl, allowing it to touch the top of the pastry cream. Place the bowl in the refrigerator and allow it to chill and set/completely thicken for about 3 to 4 hours. *Stir before spreading on the cake.
- Make the cake according to the yellow cake mix package instructions. Be sure to follow the instructions on the box to make 2 round layers.
- Once finished carefully remove the cake pans from the oven and allow them to cool on a rack for about 10 minutes before removing the cakes from the pans to finish cooling completely on a rack.
- Begin assembling the cake by adding one layer to a serving cake plate and topping it with an even layer of pastry cream filling. Leave a small amount (about ⅛-inch) empty around the edge of the cake. Add the second cake layer on top and gently press the top of the cake to allow the pastry cream to fill in the middle.
- In a saucepan over medium-low heat, add the ½ cup heavy cream and allow it to heat for 1 to 2 minutes before adding the 4 ounces dark chocolate. Stir until melted and smooth. Remove the saucepan from the heat and allow it to sit undisturbed for 2 to 3 minutes.
- Whisk the ganache, and pour on top of the cake, spreading it to the edges so that it drips on the sides of the cake. Allow it to sit for 10 minutes before slicing to serve. Enjoy!
- Store the cake in an airtight container in the refrigerator for up to 4 days.
Nutrition
*All nutritional information is based on third party calculations and is only an estimate. Each recipe and nutritional value will vary depending on the brands used, measuring methods and portion sizes per household.
Original post date 08/23/2013. Updated 11/05/2021. Updated photos are by Gabby of Cookie Dough Diaries
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Got any comments, questions, or other ideas for this Boston Cream Cake? Please share them in the comments below!
Angela Gilmore says
Oh my, I am drooling over this! Beautiful and it looks sooooo tasty!
admin says
It was very tasty...but you only need a small portion because it is very rich in taste and calories...lol