Have a Boston cream pie, support your city

First, you'll need to make the cake (yeah, a Boston cream pie is really more of a filled cake than an actual pie):

1 cup plus 2 tablespoons sifted cake flour
2/3 cup sugar
1 1/2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup milk
1/4 cup cooking oil
2 egg yolks
1 teaspoon vanilla
2 egg whites
1/4 teaspoon cream of tartar

Preheat the oven to 350 degrees. Combine flour, sugar, baking powder and salt in a medium bowl, then make a well in the center of the mixture. Add the milk, oil, egg yolks and vanilla. Beat with an electric mixer on low or medium until combined, then beat on high for 3 minutes and set aside.

In a large bowl, beat the egg whites and cream of tartar on medium or high until soft peaks form. Fold the flour/sugar/egg yolk mixture into the egg white mixture. Pour the batter into a greased 9-inch pie pan and bake for 25 to 30 minutes or until the top springs back when lightly touched. Allow to cool for a bit, then invert the pan onto a wire rack and cool completely.

Next, tackle the pastry filling:

2 cups whole, 2% or 1% milk
1/2 vanilla bean, split lengthwise with the seeds scraped out
6 egg yolks
2/3 cup granulated sugar
1/4 cup cornstarch
1 tablespoon unsalted butter

In a medium saucepan, heat the milk and vanilla bean to a boil over medium heat. Immediately remove from the heat and set aside for 10 to 15 minutes. In a bowl, whisk the egg yolks and sugar until light and fluffy. Add the cornstarch and whisk vigorously until no lumps remain, then whisk in 1/4 cup of the hot milk mixture until incorporated. Whisk in the remaining milk mixture. Reserve the empty saucepan.

Pour the mixture through a strainer back into the saucepan and cook over medium-high heat, whisking constantly, until thickened and slowly boiling. Remove from the heat and stir in the butter. Let the mixture cool slightly, then cover with plastic wrap, pressing the plastic against the surface to prevent a skin from forming. Chill for at least 2 hours. (You can make the cream up to 24 hours in advance; refrigerate it until an hour before using.)

And the final step, the ganache:

8 ounces semisweet chocolate
1 cup heavy cream, boiling

Pour the boiling cream over the chopped chocolate in a bowl and stir until melted.

To put it all together, cut the cake in half horizontally, place the lower half on a serving plate and spread it with the pastry cream. Top it with the second half of the cake, then pour the liquid ganache over the top and sides. Cool in the refrigerator until ready to serve.