Boston Cream Cupcakes

In the bowl of a stand mixer fitted with a paddle attachment, cream the butter and the sugar until fluffy and light in color, about 3 minutes.

Slowly add the eggs, vanilla, and vanilla bean paste, combining well after each addition. Scrape the bowl well with a rubber spatula then mix on high for about 1 minute until the mixture is smooth and light in color.

Sift together the cake flour, baking powder, baking soda, and salt. Add half of the flour mixture and the sour cream to the bowl. Start the mixer on low speed and slowly stream in about half the buttermilk. Mix just until combined then scrape the bowl. Add the remaining flour and slowly stream in the remaining buttermilk with the mixer on low, just until combined. Scrape the bowl again and give the mixture a few final folds with a spatula to ensure everything is incorporated.

Use a cookie scoop to divide the batter among the prepared muffin pan. Bake for 20-22 minutes, until the cupcakes spring back to the touch (or a toothpick comes out clean). The rim of the cupcakes should be slightly golden brown. Set aside to cool.

Vanilla Pastry Cream: In a medium saucepan, whisk together the egg yolks, sugar, cornstarch, vanilla bean paste, vanilla extract, and salt until well combined (the mixture should lighten in color). Slowly stream the milk into the egg mixture, while whisking.

Cook over low heat, whisking constantly until the mixture thickens and starts to bubble, about 10-15 minutes. Remove the pastry cream from heat and strain through a fine mesh sieve. Stir in the butter. Place plastic wrap directly over the custard and refrigerate until chilled.

Ganache: Place the chocolate in a heat-safe bowl. In a small saucepan, bring the heavy cream to a simmer over low heat, just until bubbles form around the edges. Immediately pour the cream over the chocolate and push down any chocolate that’s not covered. Allow to sit for 5 minutes. Gently whisk together the ganache until it's fully combined and all the chocolate is melted.

Allow the ganache to cool to room temperature until it thickens to a pipeable consistency.

Assembly: Use a cupcake corer, apple corer, or even a knife to cut a hole in the center of the cooled cupcakes. Be sure to leave a small piece at the bottom of the hole, so you don’t cut all the way down to the cupcake wrapper. Discard the centers (or save to snack on).

Fill a piping bag with the pastry cream and cut a small hole in the tip. Fill each cupcake center to the top with pastry cream. Fill another piping bag, fitted with a star tip, with the thickened ganache. Pipe a swirl of ganache on top of each cupcake. Serve right away and enjoy!