Last week’s recipe for a summery Blueberry Tart left me with some extra pastry cream on hand, and this recipe is the perfect way to use it. These are a more easily-served version of Boston Cream Pie, which is in fact not a pie at all, but instead layers of golden yellow butter cake and vanilla pastry cream, enrobed in a layer of chocolate ganache. The overall effect is impressive, right until you try to cut into it. (There is a reason custard is not commonly used as an ingredient in sturdy foundations.)

As messes go, it’s a delicious one, but not quite the dessert to hand to small children at a birthday party. The cupcake version is altogether more practical, and still just as indulgent. I leave it to you to make a batch of a dozen cupcakes from your favorite yellow cake recipe. I like this classic butter cake or this golden vanilla cake from King Arthur Flour’s web site. However, any recipe will do, as long as it’s moist and yummy. The pastry cream recipe is found here, used as the filling of the tart.

That leaves the chocolate ganache topping, and for me, that has to be Creme Fraiche Ganache from the beautiful cookbook Rose’s Heavenly Cakes by Rose Leavy Beranbaum. Beranbaum is most famous for The Cake Bible; written two decades ago, it is still an enduringly authoritative guide to making cakes that are scrumptious to see and taste. Rose’s Heavenly Cakes continues in the same literate, informed vein, and her recipes and directions are superb.

The end result of all these parts and pieces is buttery, creamy, chocolatey: all the words I love in a dessert recipe. Make no mistake, this is a sweet treat, but the Creme Fraiche Ganache adds just the right hint of tangy depth to balance the rich custard filling. These were my son’s birthday pick this year, and I think he made a wonderful choice.

Creme Fraiche Ganache
makes 1 1/3 cups, enough to frost 12 cupcakes

6 oz. quality semisweet chocolate
2/3 c. creme fraiche
4 tsp. heavy cream
2 Tbsp. unsalted butter, softened
1 tsp. vanilla bean paste or real vanilla extract

In a food processor, blitz the chocolate until chopped very fine. In a pourable 2-cup microwave-safe measuring cup, whisk together the creme fraiche and heavy cream and heat until scalding; small bubbles will form around the edges of the cream mixture, about 90 seconds in my microwave. (This can also be done in a small saucepan over medium heat.)

With the motor of the food processor running, pour the cream mixture through the tube into the chocolate in a steady stream. Process a few seconds until smooth, then add the butter and vanilla and pulse until combined. Transfer the ganache to a glass bowl and allow to sit at room temperature for an hour. Cover with plastic wrap and allow to cool until firm enough to use as frosting, several more hours at least. The ganache will keep three days at room temperature or three weeks covered and refrigerated.

To assemble cupcakes:
Using a paring knife, cut a cone-shaped piece out of the top of each cupcake, a little over an inch across and tapering to a point about an inch deep. Put a heaping spoonful of pastry cream in each little divot, then replace the cake cone. (I push mine in so that some pastry cream seeps out the side and is visible on the edges of the cupcake after frosting. If you’d prefer that your cream filling stay a surprise, gently replace the plug so that your cupcake has a more sloped top.)

Gently frost the top of each cupcake with a generous slathering of ganache, then top as desired with sprinkles or shave chocolate, or just leave pristine. These are fine to sit out for a few hours, but refrigerate the cupcakes, well-wrapped, if saving overnight. The ganache will thicken and lose its glossy sheen once refrigerated, but the cupcakes still taste delicious.

(Wiley: 2009; ISBN 978-0471781738)