Downton Abbey: Lady Edith's Marble Chocolate Tea Bread

I love a good Marbled Chocolate Tea Bread aka Chocolate Swirl. The Victorians called it Marbled Cake because the feathery swirls of chocolate are revealed when the cake (made of two batters) is sliced to make a pattern similar to Italian marble. Don't you just love food trivia?

I like to think that Lady Edith would have a slice of this wonderful Marbled Chocolate Tea Bread on her tea break while editing The Sketch. This is not a fancy cake, but it's absolutely delicious. The marbling elevates it.

DOWNTON ABBEY:  
LADY EDITH'S MARBLE CHOCOLATE TEA BREAD

Ingredients
2 cups all-purpose flour
3/4 cup sugar
1 teaspoon baking powder
1 teaspoon baking soda
1⁄2 teaspoon salt
3⁄4 cup buttermilk
2 large eggs
1 large egg white
1⁄4 cup canola oil
2 teaspoons vanilla extract
4 ounces bittersweet chocolate, chopped

Directions
Heat oven to 350 degrees F; coat 8 1/2 x 4 1/2-inch loaf pan with nonstick spray and flour lightly.
Mix flour, sugar, baking powder, baking soda, and salt in large bowl. Whisk buttermilk, eggs, egg white, oil, and vanilla in medium bowl; stir into flour mixture just until blended. Melt chocolate in top of double boiler or pot over another pot with simmering water. Stir in 1 1/3 cups batter.
Working quickly (chocolate batter will become firm and hard to swirl if standing too long), pour some of white batter over bottom of pan, then dollop with chocolate batter. Fill pan by alternating dollops of white and chocolate batter.
Pull knife through batter to swirl (quickly, don't retread).
Bake 50 minutes to one hour or until pick inserted in center comes out clean. DO NOT OVERBAKE.
Cool in pan on wire rack for 10 minutes.
Remove from pan; put cake right side up on rack to cool.