Preheat oven to 350°F (175°C). Lightly grease a mini muffin tin with cooking spray.
In a medium bowl, whisk together cake mix, flour, baking powder and salt. Set aside.
In a large bowl, cream together butter and sugar until light and fluffy. Add eggs one at a time, beating well after each addition. Add milk and vanilla and mix until combined.
Add the dry ingredients and mix until just combined. Scoop the batter into the prepared mini muffin tin, filling each cup about 3/4 full.
Bake for 12-14 minutes, or until a toothpick inserted into the center comes out clean. Allow to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.
To make the custard filling, whisk together the cream, sugar, cornstarch, egg yolks and vanilla in a medium saucepan. Cook over medium heat, whisking constantly, until the mixture thickens, about 5-7 minutes. Remove from heat and cool completely.
To make the chocolate ganache, place chocolate chips in a medium bowl. Heat cream in a small saucepan over medium heat until just boiling. Pour the hot cream over the chocolate chips and let sit for 5 minutes. Whisk until smooth.
To assemble the cupcakes, cut a small hole in the top of each cupcake. Spoon or pipe the custard filling into each cupcake. Drizzle the top of each cupcake with chocolate ganache. Serve and enjoy!
Interesting Facts
Boston Creme Pie is a classic American dessert that hails from the city of Boston, Massachusetts.
This cupcake version is a great way to enjoy all the same flavors of the traditional pie, in a fun, bite-sized treat.
You can substitute the chocolate ganache with your favorite frosting for a sweeter topping.
These cupcakes are best enjoyed the same day they are made.