Note: This post was first made in 2009 and we did not give an attribution to it. We’ve been told it is one of Carole Walter’s recipes and we want to acknowledge that. Carole is a great friend of Cooking bythe Book.

Makes one 9­-­inch Bundt cake, 10 to 12 ­servings

AT A ­GLANCE

Pan: 9­-­inch Bundt ­pan
Pan Prep: Butter generously/flour
Oven temp: ­350°F
Baking time: 55 to 60 ­minutes

Weaving together swirls of deep chocolate and creamy vanilla, this sour cream marble cake is an irresistible taste combination any time your sweet tooth calls. It never ceases to amaze me that so many people are drawn to these contrasts of flavors and colors. To achieve a beautiful marbled affect, be sure to follow the directions carefully. If the batter is overworked, the layers of chocolate and vanilla will not be clearly ­defined.

MARBLING

• 3 ounces fine­-­quality bittersweet chocolate, such as Lindt, coarsely ­chopped (see pages 387-388)
• 4 teaspoons unsalted ­butter
• 3 tablespoons Dutch­-­process cocoa ­powder
• 2 tablespoons light corn ­syrup
• 3 tablespoons ­water
• 1⁄4 teaspoon baking ­soda

BATTER

• 21⁄2 cups sifted cake flour, spooned in and ­leveled
• 11⁄2 teaspoons baking ­powder
• 1⁄2 teaspoon baking ­soda
• 1⁄2 teaspoon ­salt
• 11⁄4 cups sour ­cream
• 1⁄4 cup ­milk
• 11⁄2 teaspoons pure vanilla ­extract
• 3⁄4 cup (11⁄2 sticks) unsalted butter, slightly ­firm
• 11⁄2 cups superfine ­sugar
• 4 large ­eggs
• Powdered sugar, for ­dusting

1. Position the rack in the lower third of the oven. Heat the oven to 350°F. Generously butter a 9­-­inch Bundt pan, dust with flour, then invert the pan over the kitchen sink and tap firmly to remove the excess flour. Set ­aside.

Make the ­Marbling

2. Melt the chocolate and butter in a 2­-­quart bowl set over a pot of simmering water. (The bottom of the bowl should not touch the water.) Stir in the cocoa powder, corn syrup, and water, mixing until smooth. Remove from the heat and blend in the baking soda. Keep the chocolate mixture warm over the water bath while you prepare the ­batter.

Make the ­Batter

3. In a large bowl, thoroughly whisk together the flour, baking powder, baking soda, and salt and set ­aside.

4. In a medium bowl, combine the sour cream, milk, and vanilla. Set ­aside.

5. Cut the butter into 1­-­inch pieces and place in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed for 2 minutes, then add the superfine sugar, 1 to 2 tablespoons at a time, taking 6 to 8 minutes. Scrape down the side of the bowl as needed. Add the eggs, one at a time, at 30­-­second intervals, scraping down the side of the bowl ­again.

6. Reduce the mixer speed to low. Add the dry ingredients alternately with the sour cream mixture, dividing the flour into three parts and the sour cream into two parts. Mix just until blended after each addition. Scrape down the side of the bowl as ­needed.

7. Remove the marbling mixture from the water bath. Measure 11⁄2 cups of the batter, and add it to the marbling mixture, folding the two mixtures together ­gently.

Finish the ­Cake

8. Spoon one­-­half of the vanilla batter into the prepared pan and smooth the top with the back of a large soupspoon. Using about one­-­third of the chocolate batter, distribute spoonfuls evenly over the vanilla batter, smoothing it carefully to the edge and covering as much vanilla batter as possible. Spoon one­-­half of the remaining vanilla batter over the chocolate batter. Spread the remaining chocolate batter over the vanilla, then finish with the remaining vanilla batter. As each layer of vanilla batter is spread, cover as much of the chocolate as you can.

9. Insert a table knife almost to the bottom of the pan and gently lift the knife up, over, and down again to fold the batters together, making about 15 folds as you rotate the pan. Smooth the top of the batter with the back of a large ­soupspoon.

10. Bake for 55 to 60 minutes. The cake is done when the top is golden brown and firm to the touch, and a wooden skewer inserted in the center comes out ­clean.

11. Remove the cake from the oven and let stand on a cooling rack for 15 to 20 minutes. Cover with a cooling rack, invert the cake, and carefully lift off the pan. Cool the cake completely on the rack. Just before serving, dust the top with powdered ­sugar.

Storage: Store under a glass cake dome or covered with plastic wrap for up to 5 days.

This cake may be ­frozen.