DOUBLE-CHOCOLATE MARBLE CAKE
From BAKING CHEZ MOI, by Dorie Greenspan
Makes 8 servings
2 cups (272 grams) all-purpose flour
1¼ teaspoons baking powder
¾ teaspoon fine sea salt
1½ sticks (12 tablespoons; 6 ounces; 170 grams) unsalted butter, at room temperature
1 cup (200 grams) sugar
4 large eggs, at room temperature
1½ teaspoons pure vanilla extract
½ cup (120 ml) whole milk, at room temperature
4 ounces (113 grams) best-quality white chocolate, melted and cooled
¼ teaspoon orange or peppermint oil (optional)
4 ounces (113 grams) semisweet or bittersweet chocolate, melted and cooled
Center a rack in the oven and preheat the oven to 325 degrees F. Pull out an insulated baking sheet or stack two regular baking sheets one on top of the other. Line the (top) baking sheet with parchment paper or a silicone baking mat. Butter a 9-x-5-inch loaf pan, dust with flour and tap out the excess; set it on the baking sheet(s).
Whisk together the flour, baking powder and salt in a small bowl.
Working in a mixer fitted with the paddle attachment, or in a bowl with a hand mixer, beat the butter on medium speed for 3 minutes, or until smooth. Add the sugar and beat for another 2 to 3 minutes, then add the eggs one at a time and beat for a minute after each one goes in. The batter may curdle, but you needn’t worry. Reduce the mixer speed to low and mix in the vanilla. Still on low speed, add the flour mixture in 3 additions and the milk in 2, beginning and ending with the dry ingredients and mixing only until each addition is incorporated.
Scrape half of the batter into another bowl. Using a flexible spatula, gently stir the white chocolate into half of the batter. If you’re using the orange or peppermint oil, stir it in as well. Stir the dark chocolate into the other half of the batter.
Using a spoon or scoop, drop dollops of the light and dark batters randomly into the prepared pan—don’t think too much about the pattern—and then plunge a table knife deep into the batter and zig and zag it across the pan. It’s best to move forward and not to backtrack. Don’t overdo it—6 to 8 zigs and zags should suffice.
Bake the cake for 80 to 90 minutes, or until a tester inserted deep into the center comes out clean. Check the cake at the halfway mark, turn it around and, if it’s getting too brown, cover it loosely with a foil tent. Transfer the cake to a cooling rack and let it rest for 10 minutes, then unmold it, turn right side up on the rack and let come to room temperature.
Serving: Because of the cake’s lovely texture, you can cut it thin or thick and it will be good either way. It’s meant to be served plain, but every plain cake is good with ice cream and this one’s good with ice cream and chocolate sauce too.
Storing: Wrapped well, the cake will keep at room temperature for up to 4 days. It can be wrapped airtight and frozen for up to 2 months; defrost it in its wrapper.