Double-Down Chocolate Loaf

Ingredients

• 4 tablespoons (2 oz/56 g) unsalted butter, cut into 4 pieces
• 4 ounces (113 g) bittersweet chocolate, coarsely chopped
• 1⅜ cups (170 g) all-purpose flour
• ⅓ cup (28 g) unsweetened cocoa powder, sifted if lumpy
• 2¼ teaspoons baking powder
• ¾ teaspoon fine sea salt
• 1 cup (200 g) granulated sugar
• ⅓ cup (67 g) packed brown sugar
• ½ cup (120 g) full-fat sour cream
• 3 large eggs, at room temperature
• ⅓ cup (80 ml) neutral oil
• ½ cup (120 ml) boiling water

Instructions

1. Center a rack in the oven and preheat to 350°F (175°C). Butter a 9-inch loaf pan, dust it with flour and tap out the excess, or coat the pan with baking spray. Line the bottom and long sides with parchment for easy removal.
2. Put the butter in a heatproof bowl set over gently simmering water, making sure the bowl does not touch the water. Scatter the chopped chocolate over it and heat on low, stirring occasionally, until both are melted, smooth, and glossy. Remove from the heat and set aside briefly.
3. Whisk together the flour, cocoa powder, baking powder, and salt in a medium bowl.
4. In a large bowl, whisk the granulated sugar, brown sugar, and sour cream until smooth. Scrape in the melted chocolate mixture and whisk until thoroughly incorporated.
5. Add the eggs one at a time, whisking well after each addition. After the third egg, the mixture may resemble unset chocolate pudding; this is expected.
6. Switch to a flexible spatula. Stir in half of the dry ingredients, then add the remainder and mix until fully blended, scraping the bottom of the bowl. The batter will be thick.
7. Stir in the neutral oil until evenly incorporated. Pour in the boiling water in a slow stream and stir carefully until the batter is smooth, glossy, and noticeably looser.
8. Scrape the batter into the prepared loaf pan and smooth the top. Tap the pan gently on the counter to release large air bubbles.
9. Bake for 53 to 57 minutes, beginning to check a few minutes early. The loaf is done when it is risen, the top feels set, and a tester inserted in the center comes out with a few moist crumbs but no wet batter.
10. Cool in the pan on a rack for about 10 minutes. Run a thin knife around the short ends, lift the loaf out with the parchment, and cool completely on the rack before slicing or frosting.
11. Serve plain for a deep, clean chocolate flavor, or finish the cooled loaf with chocolate glaze, ganache, or cream-cheese frosting.