(adapted from All About Home Baking)
makes one 8” cake (fills a Nordicware 6 cup bundt pan)
For the cake-
4 oz. dark chocolate (I use Trader Joe’s Pound Plus)
½ teaspoon Medaglia D’Oro instant espresso powder
1½ cups all-purpose flour
¾ teaspoon baking powder
¾ teaspoon baking soda
¼ teaspoon salt
2 oz. (½ stick) unsalted butter, room temperature
¾ cup sugar
1½ eggs (for the half- break 1 egg into a small dish, beat with a fork, measure half)
1½ teaspoons vanilla extract
1 cup sour cream OR 1 cup nonfat plain Greek yogurt
Preheat the oven to 325 degrees F. Grease a 6 cup bundt pan.
Melt the chocolate over a double boiler, stirring until smooth. Remove from the heat, whisk in the instant espresso powder and set aside. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In the bowl of a standing mixer fitted with the paddle attachment, beat the butter and sugar until fluffy. Add the egg and a half, mixing on low to incorporate. Scrape down the sides and bottom of the bowl with a rubber scraper. With the mixer on low, add the vanilla extract and the sour cream (or yogurt) then gradually add the flour mixture.
Remove about ½ cup of the vanilla cake batter and add it to the melted chocolate, stirring to combine. Place half of the remaining vanilla batter into the bundt pan, top with half of the chocolate batter, then add the remaining vanilla batter, followed by the last of the chocolate batter. Marbleize the batters using a kitchen knife; don’t overdo it.
Bake the cake on a parchment lined baking sheet on the middle rack of the preheated 325 degree F oven for 40-45 minutes, just until the cake tests clean. Let the cake cool on a rack, turn the cake out of the pan onto a rack set over a baking sheet, and glaze with the ganache.
For the ganache-
8 oz. dark chocolate, coarsely chopped
8 oz. heavy cream
Scald the cream in a heavy bottomed saucepan. Add the chopped chocolate, let it sit for a few minutes then whisk until smooth. Pour the ganache over the cooled cake, letting it run down the sides. Wrap any leftover cake in plastic wrap; it will keep well on the counter for several days. (Any leftover ganache can be covered and refrigerated.)