Chocolate + pistachio = one heck of a birthday cake

I've always loved pistachios, but I didn't love combining those waxy, green nuts with chocolate until earlier this year, when I tried to make a batch of chocolate-pistachio biscotti. 

Somewhere along the way I screwed up the recipe, as the biscotti "loaf" fell apart when I tried to slice it after its first trip to the oven.

I tasted a bit of the crumbly batter before pitching it into the trash can, though, and the flavor nearly knocked me out of my socks.

So, when I went to make myself a birthday cake a few weeks ago, I knew it had to include those same flavors.  Thankfully, an old issue of Martha Stewart's Everyday Food magazine had just the recipe I was looking for.

Chocolate-Pistachio Torte

For the cake:

1/2 cup (1 stick) unsalted butter, cut into small pieces (plus more for pan)
1 cup all-purpose flour (plus more for pan)
1/2 teaspoon salt
1/4 teaspoon baking powder
8 ounces semisweet chocolate, coarsely chopped
1 1/4 cups sugar
1 teaspoon vanilla extract
2 large eggs
1/2 cut low-fat buttermilk
1/4 cup shelled unsalted pistachios, coarsely chopped

** Note: If you're like me and you tend to use salted (rather than unsalted) butter, decrease the salt to 1/4 teaspoon, if not less.

For the frosting:

1/2 cup heavy cream
4 ounces semisweet chocolate, coarsely chopped
1/4 cup shelled unsalted pistachios, coarsely chopped

Start with the cake: Preheat your over to 350 degrees. Butter and flour an 8-inch round cake pan and then line the bottom with parchment paper. In a medium bowl, whisk together the flour, salt and baking powder and set aside.

In a small saucepan over low heat, melt the butter and chocolate, stirring frequently to avoid scorching. Remove from heat and whisk in the sugar and vanilla, then the eggs, buttermilk and pistachios. Fold in the reserved flour mixture just until it's combined.

Pour the resulting batter into the prepared cake pan and bake for 60-70 minutes--until a toothpick inserted into the center comes out with a few moist crumbs attached to it. Let the cake cool in its pan for about 5 minutes and then run a knife around the edge and invert it onto a wire rack. Remove the parchment paper and let the cake cook completely (2-3 hours).

To make the frosting: In a small saucepan, bring the cream to a simmer. Remove from the heat and then add the chocolate. Let stand for about 5 minutes, then whisk until smooth. Cool the mixture until it falls back in ribbons when lifted with a spoon, about 5 minutes more.

Set cake on a serving platter and tuck strips of parchment paper around the edge to prevent the ganache from dripping onto the platter. Pour ganache onto the center of the cake and, using a spatula or even a butter knife, spread it evenly over the top and sides of the cake. (If you push the ganache to the edge of the top of the cake, it will naturally drip down the sides and cover them naturally.)

Let the ganache set for about 30 minutes and then remove the parchment paper from under the cake. Sprinkle the top with the reserved pistachios and serve.