Pound cake is so called because it is traditionally made with a pound each of flour, sugar, butter, and eggs. Take, for instance, this mid-18th-century recipe:
Take a Pound of Butter, beat it in an earthen Pan, with your Hand one Way, till it is like a fine thick Cream; then have ready twelve Eggs, but half the Whites, beat them well, and beat them up with the Butter, a Pound of Flour beat in it, and a Pound of Sugar, and a few Carraways; beat it all well together for an Hour with your Hand, or a great wooden Spoon. Butter a Pan, and put it in and bake it an Hour in a quick Oven. For Change, you may put in a Pound of Currants cleaned wash'd and pick'd
You will notice that this recipe does not call for any Saleratus or Horsford’s Bread Preparation, and that is because baking soda and baking powder (as they’re known today) weren’t commercially available until the mid-19th century. Before that, pound cake was unleavened and consequently leaden. The development of chemical leaveners was a godsend for many baked goods, but perhaps none so much as pound cake. A pound cake without baking powder is heavier than the loudest, most ominous Black Sabbath track.
Other modern pound cake developments have been less auspicious. These days, “pound cake” recipes often boast yogurt, buttermilk, sour cream, and even plain old milk in their ingredients lists. Judging from these recipes, you’d think any regular cake magically becomes a pound cake just by being baked in a loaf pan. This isn’t the case. Yogurt cake is good, for sure, but adding yogurt dilutes the dense, buttery richness of real pound cake. Let’s all agree that pound cake should have no liquid in it besides butter, eggs, and perhaps some vanilla or almond extract (or, as a trusted colleague emphatically advises, rum).
And maybe some melted chocolate. I’m not big on pure chocolate pound cake, but marble pound cake, with its balanced swirls of chocolate and vanilla crumb, is the perfect way to create some bite variety in a usually monotonous dessert. And it’s the perfect symbolic Valentine’s Day treat for couples: two distinct entities, harmonious entwined, each improved by the presence of the other … or it can also symbolize how you and your ex are total opposites embroiled in eternal conflict. It's an edible Rorschach test, if you will. And marble pound cake is easier than it looks: All it takes is a little restraint while you’re stirring and swirling.
This recipe is technically more like a half-pound cake than a pound cake—it contains roughly half a pound each of flour, sugar, butter, and eggs—but if you want to make a batter with four sticks of butter in it, then double the recipe, bake it in a 16-cup tube pan, and start checking it after an hour in the oven.
Marble Pound Cake
Yield: 10 to 12 servings
Time: 1¾ to 2 hours, largely unattended
Oil or butter for greasing the pan
2 ounces semisweet chocolate
1 cup (2 sticks) unsalted butter, softened
1⅓ cup sugar
5 large eggs or 7 small eggs
1 teaspoon vanilla extract
¼ teaspoon salt
1½ teaspoons baking powder
1¾ cups all-purpose flour
½ teaspoon almond extract
1. Heat the oven to 350°F. Grease an 8- or 9-inch loaf pan. Put the chocolate in a small saucepan over low heat; cook, stirring frequently, until melted, 1 to 2 minutes. Set aside.
2. Beat the butter and sugar* with the paddle attachment of a stand mixer (or with a handheld electric mixer) until light and fluffy. Add the eggs, vanilla, and salt, and beat on high speed until thick and voluminous, 2 to 3 minutes. Gently stir in first the baking powder, then the flour, just until combined.
3. Transfer about half of the batter to a separate medium bowl. Fold in the chocolate and almond extract. Dollop about half of the vanilla batter into the greased pan, followed by about half of the chocolate batter. Repeat. Drag a butter knife through the batter to create swirls.
4. Bake until a toothpick inserted into the center of the cake comes out clean, 1¼ to 1½ hours. Cool thoroughly, then slice and serve. (Store leftover cake at room temperature for up to a few days.)
Correction, Feb. 18, 2014: The recipe in this post originally contained an erroneous reference to brown sugar.