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Delicious Boston Cream Cupcakes topped with chocolate and filled with vanilla custard
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Boston Cream Cupcakes

Delightful mini cupcakes filled with rich pastry cream and topped with luscious chocolate ganache.
Prep Time20 minutes
Cook Time20 minutes
Total Time40 minutes
Course: Dessert
Cuisine: American
Keyword: Baking, Boston Cream Cupcakes, Cupcakes, dessert, Indulgence
Servings: 12 cupcakes
Calories: 250kcal

Ingredients

For the Cupcakes

  • 3/4 cup unsalted butter, softened Rich and creamy, providing a base of flavor.
  • 1/2 cup sour cream Adds tenderness and subtle tang.
  • 1 cup granulated sugar Sweetness that balances the cupcakes perfectly.
  • 2 tsp pure vanilla extract Infuses a warm, aromatic note.
  • 3 large egg whites For a light and airy texture.
  • 1/4 tsp baking soda Helps with rising, ensuring fluffy cupcakes.
  • 1/2 cup whole milk Brings moisture and richness.
  • 1 tsp baking powder Essential for a good rise.
  • 1 2/3 cups all-purpose flour Creates the structure of the cupcakes.

For the Pastry Cream

  • 3 tbsp granulated sugar Sweetens the velvety filling.
  • 1 cup heavy cream Provides a rich, creamy texture.
  • 1 tbsp cornstarch Thickens the pastry cream beautifully.
  • 2 large egg yolks Rich in flavor for a custard-like experience.
  • 1 tsp pure vanilla extract Adds depth of flavor.

For the Ganache

  • 1/2 cup heavy cream Ensures the ganache is luscious and silky.
  • 6 oz semi-sweet chocolate, chopped Forms the decadent topping.

Instructions

Make Cupcakes

  • Preheat your oven to 350°F (175°C) and line a muffin pan with cupcake liners.
  • In a large mixing bowl, combine the flour, granulated sugar, baking soda, and baking powder. Whisk gently.
  • Add the softened butter, egg whites, sour cream, milk, and vanilla extract into the bowl.
  • Using an electric mixer, beat until the batter is smooth and creamy.
  • Fill each cupcake liner about 2/3 full with batter. Bake for 18 to 20 minutes or until a toothpick comes out clean.
  • Remove from the oven and allow the cupcakes to cool completely before transferring to a wire rack.

Prepare Pastry Cream

  • In a saucepan, heat 1 cup of heavy cream over medium heat until just simmering.
  • Whisk together egg yolks, 3 tablespoons of granulated sugar, and cornstarch until smooth.
  • Pour the hot cream into the egg mixture gradually, whisking constantly.
  • Return the mixture to the saucepan and cook over low heat, stirring continuously until thickened.
  • Stir in vanilla extract, transfer to a bowl, cover with plastic wrap, and chill.

Make Ganache

  • In a small saucepan, heat the remaining half-cup of heavy cream over medium heat until it simmers.
  • Place the chopped chocolate in a bowl and pour the hot cream over it.
  • Allow it to sit for about 1 minute, then stir until smooth.

Fill Cupcakes

  • Cut a small center hole out of each cooled cupcake.
  • Fill each hollow with a spoonful of ganache and place in the freezer for about 10 minutes to set.
  • Once set, fill the cupcakes with the chilled pastry cream.

Finish with Ganache

  • Dip the tops of each cupcake into the remaining ganache.
  • Allow the topped cupcakes to set before serving.

Notes

For a hint of citrus, consider adding lemon zest. Store leftover cupcakes in an airtight container in the fridge for up to 3 days. Freeze unfilled cupcakes tightly for up to 2 months.