Introduction

These Boston Cream Pie Cupcakes capture all the classic flavors of the beloved dessert in a convenient cupcake form. Featuring moist vanilla cupcakes filled with rich pastry cream and topped with smooth chocolate ganache, they make a delightful treat for any occasion.

The image shows seven vanilla cupcakes sitting on a black cooling rack. Each cupcake has two visible layers: a light yellow, smooth cake base wrapped in a white cupcake liner, and a thick swirl of dark chocolate frosting on top, shaped like a rose with a glossy texture. The cooling rack rests on a blue and white patterned cloth, all set against a white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

6 tbsp (84g) unsalted butter, room temperature
3/4 cups (155g) sugar
6 tbsp (86g) sour cream, room temperature
2 tsp (10ml) vanilla extract
3 large egg whites, room temperature
1 1/4 cups (163g) all purpose flour
2 tsp (8g) baking powder
¼ tsp salt
6 tbsp (90ml) milk, room temperature
2 tbsp (30ml) water, room temperature
2 egg yolks
6 tbsp (78g) sugar
1 1/2 tbsp cornstarch
1 cup + 2 tbsp (270ml) milk
1 tbsp (14g) salted butter
1 tsp vanilla extract
12 oz (338g) semi sweet chocolate chips
2 tbsp (30ml) light corn syrup
3/4 cup + 2 tbsp (210ml) heavy whipping cream

Instructions

Step 1: Preheat the oven to 350°F (176°C) and line a cupcake pan with cupcake liners.
Step 2: In a large bowl, cream together the butter and sugar until light and fluffy, about 3-4 minutes. This step is important for a tender cake.
Step 3: Add sour cream and vanilla extract, mixing well to combine.
Step 4: Add the egg whites in two batches, mixing thoroughly after each addition. Scrape down the bowl sides as needed to incorporate all ingredients.
Step 5: In a separate bowl, whisk together the flour, baking powder, and salt. In a small measuring cup, combine the milk and water.
Step 6: Add half of the dry ingredients to the batter and mix until combined. Stir in the milk mixture, then add the remaining dry ingredients, mixing to combine completely. Scrape the bowl sides again if needed.
Step 7: Fill cupcake liners about halfway with batter. Bake for 15-17 minutes or until a toothpick inserted comes out with a few moist crumbs.
Step 8: Let cupcakes cool in the pan for 2-3 minutes, then transfer to a wire rack to cool completely.
Step 9: To make the pastry cream, gently beat the egg yolks in a medium bowl and set aside.
Step 10: In a large saucepan, combine sugar, cornstarch, and milk. Stir until smooth.
Step 11: Cook the mixture over medium-high heat, stirring constantly, until it thickens and starts to bubble.
Step 12: Reduce heat to medium and simmer for 2 minutes, then remove from heat.
Step 13: Temper the egg yolks by whisking a small amount of the hot milk mixture into them, then slowly adding the yolk mixture back into the saucepan. This prevents scrambling.
Step 14: Return the pan to the heat and bring to a gentle boil for 2 minutes, stirring continuously until thick.
Step 15: Remove from heat, stir in butter and vanilla extract until smooth. Let the pastry cream cool to room temperature.
Step 16: For the chocolate ganache, place chocolate chips and corn syrup in a large bowl.
Step 17: Heat heavy cream to boiling, then pour over the chocolate. Let sit 3-5 minutes before whisking until smooth.
Step 18: Chill the ganache in the refrigerator for 1-2 hours until firm.
Step 19: Once cupcakes and fillings are cool, cut out the centers of the cupcakes using a cupcake corer or knife.
Step 20: Fill each cupcake center with pastry cream.
Step 21: Pipe or spread the chocolate ganache on top of each cupcake. To pipe roses, start in the center and swirl outward with a piping tip, completing 2-3 rotations per cupcake.
Step 22: Refrigerate cupcakes until ready to serve. Serve closer to room temperature for the best texture, as ganache firms when cold. Enjoy within 3-4 days.

Tips & Variations

Use room temperature ingredients to ensure a smooth batter and even baking.
For a lighter filling, you can fold whipped cream into the pastry cream once it’s cooled.
If you don’t have a cupcake corer, gently cut out cupcake centers with a small knife and scoop cream in with a teaspoon.
Try using dark chocolate instead of semi-sweet for a richer ganache flavor.

Storage

Store the cupcakes in an airtight container in the refrigerator for up to 3-4 days. Because of the ganache and pastry cream filling, refrigeration is necessary. Bring cupcakes to room temperature before serving to soften the ganache for the best experience.

How to Serve

A close-up of a single cupcake with three layers. The bottom layer is light yellow fluffy cake with a moist texture, hollowed out in the middle to reveal the middle layer, which is creamy pale yellow vanilla custard filling. The top layer is a thick swirl of smooth, dark brown chocolate frosting, glossy and rich, decorated with soft, flowing waves. The cupcake sits on a black metal cooling rack, with other cupcakes blurred in the background over a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make the cupcakes ahead of time?

Yes, you can bake the cupcakes a day ahead and store them cooled and uncovered to maintain softness. Assemble with pastry cream and ganache on the day you plan to serve for optimal freshness.

What if I don’t have sour cream?

You can substitute sour cream with plain yogurt or buttermilk in equal amounts. This will keep the cupcakes moist and tender.