Last week was my sister’s birthday. I didn’t come as much of a surprise, really, because I have quite the analytical mind, and a careful observation has led me to the conclusion that this phenomenon happens every 8th of December, year in, year out. At least it always has. Of course, just because the sun has risen every morning for as long as we can remember doesn’t mean it won’t one day set and refuse to rise again. But one cannot live in such troubling uncertainty, one needs to rely on a few solid beliefs, and the yearly occurrence of my sister’s birthday is not the least of them.
This year, I offered to bake her a birthday cake, to be served at the party she threw last Saturday night. Our mother had already made one for our little family celebration (there is no such thing as celebrating a birthday too many times) : it wasn’t technically a birthday cake, but rather a beautiful pear and chestnut charlotte, made with slices of her homemade biscuit roulé (the French jelly roll). Impressive and particularly delicious, it was gulped down between the four of us — you know, a charlotte just doesn’t keep that well.
To me, cakes pretty much fall under two categories, chocolate and non-chocolate, so I asked the birthday-girl-to-be which kind she wanted. Her reply was that she simply wanted a surprise cake, so I followed my deeper instincts and went, well, the chocolate route.
I still had some of that super-cool super-good pistachio paste, and since chocolate and pistachio are such good friends, I chose to make a chocolate and pistachio cake, starting with my favorite and highly adaptable cake recipe. I made half of the cake batter chocolate (with cocoa powder and chocolate chips, which are in fact “ganache drops” if you please) and covered it with the other half of the batter, made pistachio by mixing in pistachio paste and chopped pistachios.
I was in fact shooting for two clean layers, but apparently pistachio and chocolate are better friends than even I suspected, and they got themselves a little action in the oven, ending up in a marbled tangle, accidental but pretty. I then covered the cake in a thick blanket of ganache — if life has taught me one thing it’s that you can’t go wrong with ganache. Ever.
I named the cake Chocolate and Pistachio Surprise Cake because you can’t tell it is pistachio until you slice it and oh, look! there’s a pistachio cake inside that chocolate cake! Of course, you cannot tell people the name of the cake before you’ve sliced it, otherwise there goes your surprise, but I am highly amused by this little name-giving business, what are you gonna do.
The appropriate number of candles were placed on the cake and blown out with talent, the cake was cut in as many slices as I could and passed around. I was pretty pleased: the crumb was nice and moist, the pistachio taste fragrant but not artificial, the ganache luscious (you can’t go wrong with ganache I tell you), the guests were very appreciative (one gourmand in particular, hi Arthur!) and my sister loved it, which was really what mattered the most…
- 270 g (2 C) flour
- 2 tsp baking powder (1 envelope)
- 1 tsp baking soda
- 150 g (2/3 C) butter, at room temperature
- 300 g (1 1/4 C) white sugar
- 4 eggs
- 1 1/2 C (3 x 125 ml) plain yogurt or sour cream
- 1 1/2 tsp vanilla extract
- 2 Tbsp unsweetened cocoa powder
- 60 g (1/3 C) chocolate chips
- 2 Tbsp pistachio paste
- 60 g (1/3 C) shelled pistachios, chopped
- Preheat your oven to 180°C (360°F). Grease a 25-cm (10-inch) cake pan, preferably nonstick with a removable bottom.
- Prepare the chocolate batter. In a food processor, mix together half of the sugar and half of the butter until fluffy. Add in two of the eggs, one at a time, mixing between each. Add in half of the yogurts and all the vanilla extract, mix again.
- In a medium bowl, combine half of the flour with half of the baking powder, half of the baking soda and all of the cocoa mixture.
- Add the flour mixture into the food processor and mix again until just combined. Pour the batter into the cake pan, and reserve in the refrigerator.
- Rinse the bowl of the food processor, and prepare the pistachio batter: mix together the rest of the sugar, the rest of the butter and the pistachio paste. Add in the two last eggs, one at a time, mixing between each. Add in the rest of the yogurts and mix again.
- In a medium bowl, combine the rest of the flour with the rest of the baking powder and baking soda, and all of the chopped pistachios. Add into the food processor and mix again until just combined.
- Take the cake pan out of the fridge, and sprinkle the chocolate chips evenly over the surface of the chocolate batter. Gently pour the pistachio batter on top, and smooth out the surface with a spatula.
- Put into the oven to bake for about an hour or until a cake tester comes out clean.
- Let rest for five minutes on the counter, then remove cake from the pan, and transfer to a rack to cool completely.
- Prepare the ganache. Melt the dark chocolate with the whipping cream in a double boiler (or in a bowl set over a saucepan of simmering water), stirring with a spoon regularly until completely melted and velvety. Let the ganache rest until it has thickened a bit, about 30 minutes, and frost the cake using a small spoon.
- You can either wait until the ganache has cooled and set before serving, or frost the cake just before you serve it, but the cake itself needs to have cooled down completely, it tastes better that way.
This post was first published in December 2004 and updated in July 2016.