My cake took a little longer to bake. I baked at 325°F for 50 minutes and then lowered it to 300°F and baked for 20 more minutes. Maybe thats why my cake developed a "crunchy crust" after it cooled. Also, my cake sank slightly. I think my baking soda/powder ratios were off. I might increase both next time by quarter teaspoon. This is definitely worth making again!
Everyday Chocolate Cake
by Smitten Kitchen
1/2 cup (1 stick) unsalted butter, softened
1 cup firmly packed light brown sugar
1/2 cup granulated sugar
1 large egg, at room temperature
1 cup buttermilk
1 teaspoon vanilla extract
1 1/2 cups all-purpose flour
3/4 cup Dutch cocoa powder
1/4 teaspoon baking soda
1/2 teaspoon baking powder
1/4 teaspoon salt
Preheat the oven to 325°F. Butter and lightly flour a 9×5x3-inch loaf pan, or spray it with a butter-flour spray. In a large bowl, on the medium speed of an electric mixer, cream the butter until smooth. Add the sugars and beat until fluffy, about 3 minutes. Add the egg and beat well, then the buttermilk and vanilla. Don’t worry if the batter looks a little uneven. Sift the flour, cocoa, baking soda, baking powder and salt together right into your wet ingredients. Stir together with a spoon until well-blended but do not overmix. Scrape down the batter in the bowl, making sure the ingredients are well blended.
Pour the batter into the prepared loaf pan. Bake for 60 to 70 minutes, or until a cake tester inserted into the center of the loaf comes out clean. Cool in pan on a rack for about 10 to 15 minutes, at which point you can cool it the rest of the way out of the pan.