Boston Cream Pie. Look Ma, No Screw Ups!


Tom: Whoa, this actually looks like a Boston Cream Pie
Me: What do you mean?  That’s what it is.
Tom: I know, but remember the German Chocolate Cake?  This thing looks real.  Just like the picture on my container of Yoplait!

I’m sure I sound like a broken record here, but I am so NOT a baker. Just the process of it–the precise measuring, the science, the rules–is too much for me. And then you have to worry about all the possible problems–overmixing, overbaking, underbaking, bad baking soda, sunken cakes, deep fried aardvarks. Fuggetaboutit! Not to mention that no matter how little or much I bake, I always manage to get about 2 lbs. of flour all over the kitchen and myself, in Lucille Ball-like fashion.

But, because I sometimes like to torture myself, I continue to make attempts at becoming a better baker. You may remember the fiasco that was Tom’s birthday cake (err..trifle) last year. Yeah, that didn’t turn out so well. So this year I wanted to actually make a proper cake for my husband’s birthday.

German chocolate cake on my hit list, I looked around some favorite recipe sights to see if another type of cake caught my eye. When I came across the Cook’s Illustrated recipe for Boston cream pie, I knew it had to be the one. Tom likes yellow cake with chocolate frosting, so this was pretty similar. And, I’m not going to lie–I personally love Boston cream pie. And I was going to be eating some of it too, afterall.

But this cake instilled fear in me, just as the German chocolate cake had. This one required pastry cream. I’ve never made pastry cream before and I do have a bit of a fear of all things involving egg tempering and the like. It took me a while to perfect avgolemono and pastry cream is even scarier because you actually cook the eggs on the stovetop slowly. And as we know, I have an unlevel stovetop that has two settings for the burners: insanely high and so-low-the-flame-will-go-out-6-times-while-you’re cooking. And then there’s the cake itself. First of all a sponge cake requires precise folding of all ingredients, soft (not overmixed!) peaks of egg whites and the like. Oh and then you have to actually get it out of the oven at the right time and invert it onto a plate and then a rack without half of it staying in the pan.

When I finished making the pastry cream and it was a perfect consistency, tasted great, and looked even better, I did an internal dance of joy. When I properly folded the sponge cake batter, took the cakes out of the oven before they were overbaked and got BOTH of them out of the pan in one piece, I did an external dance of joy.

Seriously, I am so proud of myself. Some of you seasoned bakers probably feel sorry for me for being so excited over pastry cream and sponge cakes but this is a big step for me!

The cake turned out perfect. I never bothered to make sure we have rum because we always do. Of course when I went to get the bottle from the bar, all we had was 151 and I didn’t really feel like using that in the custard, so I just used extra vanilla. I also used a more straightforward ganache rather than the CI version (which uses vanilla and corn syrup). Other than that, I stayed true to the recipe and this cake was delicious!

These pictures didn’t turn out as great as I would like, which is sad because I wish it looked as good as it tasted! Also the chocolate ganache that swoops down into the cake when you are slicing it doesn’t photograph quite as well as the perfect piece Cook’s Illustrated managed to get with the help of their food stylists and photoshopping. But puh-lease! I was able to make pastry cream, sponge cakes (and not just any sponge cakes…the kind that actually came out of the pan in one piece), ganache and put it all together to make a delicious layer cake. Finally.

Boston Cream Pie
adapted from Cook’s Illustrated

Sponge Cakes
1/2 cup cake flour
1/4 cup unbleached all purpose flour
1 tsp. baking powder
1/4 tsp. salt
3 Tbsp. milk
2 Tbsp. unsalted butter
1/2 tsp. vanilla extract
5 eggs, room temperature
3/4 cup granulated sugar, divided

Pastry Cream
2 cups milk
6 large egg yolks
1/2 cup granulated sugar
1/4 tsp. table salt
1/4 cup corn starch, sifted
2 tsp. vanilla extract
2 Tbsp. unsalted butter (optional)

6 oz. semisweet chocolate, chopped
3/4 cup heavy cream
1/2 Tbsp. unsalted butter

Make the pastry cream first. Heat milk in a small sauce pan until hot but not simmering. Whisk yolks, sugar, and salt in another large saucepan until mixture is thick and lemon colored, 3-4 minutes. Add cornstarch and whisk to combine.

Slowly whisk in hot milk. Cook mixture of medium-low heat, whisking constantly and scraping pan sides and bottoms as you stir, until mixture becomes thick and pudding-like consistency, about 10 minutes. Off the heat stir in the vanilla and butter (if using). Pour the pastry cream into a clean bowl and immediately place plastic wrap so that it is touching the top of the cream, so a skin doesn’t form. Let the mixture cool at room temperature for a bit before moving it to the fridge to cool completely, a few hours (or overnight).

Then make the cakes. Adjust oven rack in the lower-right position and preheat the oven to 350. Cut out two pieces of parchment paper to fit over the bottoms of the pans (8 or 9″ round cake pans). Grease & place a parchment round in each pan.

Sift together flours, baking soda and salt in a bowl and set aside. Heat the milk and butter in a small saucepan over low heat until the butter melts. Remove from heat and add the vanilla. Cover and keep warm.

Separate 3 of the eggs, placing the whites in one bowl and the yolks in another (put either or both in your mixing bowl, if you are using a stand mixer). Place the remaining two eggs in the same bowl as the yolks.  Beat the 3 whites on high speed until foamy. Gradually add in 6 Tbsp. of sugar, continuing to beat whites to soft, moist peaks. Do not overbeat.

Beat the egg yolks and 2 eggs along with the remaining 6 Tbsp. sugar on medium-high until eggs are very thick and pale in color, about 5 minutes (will take longer if hand mixing). Add beaten eggs to whites.

Sprinkle the flour mixture over the beaten eggs and whites. Fold very gently 12 times with a large rubber spatula. Make a well in one side of the batter and pour milk mixture into bowl. Continue folding until batter shows no trace of flour and whites and eggs are evenly mixed, about 8 more times.

Immediately pour the batter into the prepared pans. Bake for 16 minutes for 9″ pans and about 20 minutes for 8″ pans. Immediately run a knife around the perimeter of the cakes to loosen. Invert the cakes onto a large plate. Peel off the wax paper, and then invert them onto a cooling rack (next time I will just invert them right onto the cooling rack; no reason to risk breaking them twice!).

Finally, make your ganache. Place your chopped chocolate in a bowl. Bring the butter and cream to a boil in a saucepan.  Pour the boiling cream over the chocolate and let it sit for 3 or 4 minutes. Stir until smooth. Let it sit another minute or two to become more pourable.

Ready to assemble the cake? Place some parchment or wax paper strips on a large plate or stand (something easy to pull out from under the cake). Place one of the cakes on the plate. Top with the pastry cream and spread the cream to the edge of the cake in an even layer.  Place the second cake on top of the cream. Pour the ganache right in the center of the cake, and let it ooze around the cake and down the sides. Smooth with an offset spatula (which, of course, I don’t have) or something else that will allow you to get an even layer of the ganache.

Cover and refrigerate any leftovers.

Boston Cream Pie. Look Ma, No Screw Ups!

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