6 large eggs, at room temperature
1 cup sugar
10 ounces dark (semisweet or bittersweet) chocolate, coarsely chopped (I buy the bittersweet chocolate chunks)
8 ounces (2 sticks) unsalted butter
1 teaspoon ground cardamom
1 cup roasted, unsalted, shelled pistachios (or more if you like pistachios)
Preheat the oven to 300 degrees.
Line the bottom of a 9-inch springform pan with parchment paper.
Using a stand mixer, combine the eggs and sugar, beating on high speed for 10 minutes, The mixture should be light and creamy and doubled in volume.
Heat about 1 inch of water in a medium saucepan, over medium heat. Place a medium stainless-steel mixing bowl on top, fitting it snugly over the opening of the saucepan. Place the chocolate and the margarine or butter in the bowl and let them melt. Remove the bowl from the heat and stir until smooth and well combined.
Add the pistachios and cardamom to the bowl of a mixer or food processor and process until very finely ground.
Fold a little of the warm chocolate into the beaten egg-sugar mixture. It will deflate which is normal.
Fold in the remaining chocolate, then the nut-spice mixture, stirring just until mixed. Pour into the prepared pan and bake for 30 minutes; the top may crack a bit and the center of the cake will be soft.
Turn off the oven and leave the cake inside for 10 minutes, with the oven door cracked open.
Remove from oven to a wire rack to cool completely before serving.
If desired, prepare your favorite chocolate icing/glaze and ice the top of the cake, allowing it to drible down the sides of the cake. Top with additional pistachios if desired.