Boston Cream Pie with Mascarpone Custard - and that's saying a lot

Now THAT is a fine dessert. Sam, Amanda and I all got together and decided that a Boston Cream Pie would be the best dessert we could possibly make for the night. And Amanda's mom had a secret recipe for a custard made with mascarpone cheese and vanilla beans which provided the perfect touch to this fantastic dessert. Boston Cream Pie isn't quite a pie, it's a cake rather. Two layers of soft sponge cake with a custard layer in between, topped with a shiny chocolate ganache. Sound like a challenge? It certainly was, and we took it on with full force. Even with our amateur skills, we pulled off a fine dessert and you can do the same. Shall we get onto the recipe? This one primarily came from here:

http://www.foodnetwork.com/recipes/gale-gand/boston-cream-pie-recipe/index.html

with the exception of Amanda's mother's custard recipe which we used in place of the custard provided. And below you'll find everything you need to replicate this fine dessert at home. (Should you want to forego the expense of mascarpone and stick with the foodnetwork.com recipe for the custard, you would be absolutely fine - but let me tell you, this custard is the most delicious custard I have EVER tasted. No lies. You'll find our modified recipe below:

WHAT YOU'LL NEED:

THE CAKE:
-1 cup plus 2 tablespoons all-purpose flour (cake flour would make it fluffier if you have it, but it's a minor detail)
-2/3 cup sugar
-1 1/2 teaspoons baking powder
-1/4 teaspoon salt
-1/2 cup milk
-1/4 cup vegetable oil
-2 eggs (separated - you'll need both yolks and both whites separately)
-1 teaspoon vanilla extract
-1/4 teaspoon cream of tartar (this helps the egg whites get all fluffy when you beat them)

THE CUSTARD:
-2 cups milk (avoid skim milk if you can, whole milk would be ideal)
-1 cup sugar
-1 vanilla bean and seeds, split and scraped (this adds a BEAUTIFUL touch, but a teaspoon of vanilla extract would suffice should these be unavailable)
-a pinch of salt
-4 eggs
-1/3 cup all-purpose flour
-8 oz mascarpone cheese (most mascarpone cheese comes in an 8 oz container)
-2 tablespoons butter (unsalted and chilled, ideally)
-2 tablespoons vanilla extract

THE GANACHE (OR CHOCOLATE ICING, BUT GANACHE IS SO MUCH BETTER):
-8 oz semi-sweet chocolate, finely chopped
-1 cup heavy cream


Okay, sounds like a lot of ingredients - and it is. And it sounds like a lot of detailed work - and it is. This is about to be a long post, but if you take everything step by step, proceed with care, and BE PATIENT, everything will come together perfectly. I'll even number the steps for you to make it a bit easier.

BOSTON CREAM PIE - INSTRUCTIONS
1. Preheat the oven to 350 degrees. (Easy enough)
2. Combine the flour, sugar, baking powder, and salt in a mixing bowl and make a well in the center after combining. Add the milk, oil, egg yolks, and vanilla to the well:
3. Using an electric mixer, beat on a low/medium setting until combined, and continue beating for three minutes.
4. In another (large!) mixing bowl beat the egg whites and cream of tartar until soft peaks form. This will be a few minutes but you'll know when you get there. Amanda demonstrates:
5. Now you're going to pour the egg yolk mixture into the egg white mixture, and fold them together, which will incorporate them without deflating the egg whites you just whipped to perfection. If they deflate too much, your cake will be less fluffy, so using a spatula, just fold the mixtures on top of each other until they look well-incorporated. Gently pour your mixture into a greased 9 inch cake pan and bake at 350 degrees for 25-30 minutes or until the center of the cake springs back after lightly pressing. When it's done, remove and invert the cake onto a wire rack and let it cool completely.
6. We'll start the custard now, while the cake bakes. Place milk and sugar in a large saucepan and prepare the vanilla bean by slicing it down the center and scraping the seeds out. Place the empty bean and all the seeds in the milk and sugar mixture and heat over medium heat until the sugar dissolves.
7. In a separate bowl, whisk the 4 eggs until blended and gradually add the flour, whisking until most of the lumps are gone. The next step is a bit tricky.
8. You're going to temper the eggs with the hot milk mixture. Because adding hot liquid to eggs could essentially COOK them, we want to avoid this, so that our cake is not filled with scrambled eggs. Take 1 cup of the hot milk mixture (which you will want to strain, as to remove the large vanilla husk and seeds) and slowly add that 1 cup of hot milk mixture to the eggs, constantly whisking so that they heat slowly and evenly. Strain the rest of the milk mixture into the egg mixture and then add the whole thing back to the saucepan - it needs to be heated again.
9. Constantly whisk this mixture (which is slowly becoming your custard) until it begins to boil. It will slowly start to thicken as it boils, and let it boil for one minute to remove the starchy flavor from the flour.
10. While this boils (remember to whisk it constantly!) Put your mascarpone cheese and the butter in a bowl and mash them to combine. After your mixture has boiled, pour it over the mascarpone and butter, add the vanilla, and stir until it's entirely incorporated. Then, cover with plastic wrap, making sure to press the plastic wrap against the surface of the custard to prevent a skin from forming. This would be gross otherwise. Refrigerate this until it is chilled. DO NOT ATTEMPT USING THE CUSTARD BEFORE IT IS CHILLED. This requires patience, and is crucial to a successful pie.
11. You can proceed to this step once your custard is chilled and your cake is cool. Cut the cake in half horizontally, creating two separate layers of cake. Spread your chilled custard on to the bottom half and place the other half on top, making sure that the flattest part is facing upward. Let that sit while you make the ganache.
12. For the ganache, first begin by finely chopping ALL of the chocolate - it needs to be able to melt quickly. Then heat the cup of heavy cream over medium heat until it begins to boil. In a small bowl, pour the boiling cream over your chocolate and whisk until the chocolate is melted and you have a beautiful, shiny chocolate sauce. That's your ganache! It's so easy!
13. Transfer your cake to a serving plate and pour the ganache over your cake and custard layers, making sure it spreads evenly and doesn't end up thicker in certain places. Let it cover the top and sides of your cake, and store in the refrigerator.

CONGRATULATIONS! YOUR BOSTON CREAM PIE IS DONE! My advice: let it chill in the refrigerator for an hour. This dessert is best served cold, and with that rich vanilla custard, fluffy sponge cake, and semisweet chocolate ganache, you will be SO greatly rewarded for your patience. I'll include a picture of our finished product, although we ended up making a mess all over our serving tray with our ganache. It goes to show that you don't have to use it ALL :)
This turned out so well, and any pratfalls we encountered I've made sure to explain in detail so you guys won't encounter the same ones and YOUR boston cream pie can turn out even better! Definitely do give this a try, even without the vanilla beans and mascarpone this dessert can be perfectly gourmet.

Special thanks to Sam Draxler and Amanda Kohr for their fine culinary help, without which, this chef would have been stumbling over himself trying to get this all sorted out!

Signing off for now (only a third of this fine cake remains!),

Alex