- 1 3/4 cups all-purpose flour
- 3/4 cup cocoa powder
- 1 3/4 teaspoons baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon ground cinnamon
- 2 1/4 cups light brown sugar
- 1 1/3 cups butter, at room temperature
- 3 eggs
- 1 1/2 teaspoons vanilla extract
- 1 1/2 cups Irish stout beer (such as Guinness®), at room temperature
- 1 cup chopped pecans (optional)
- Preheat oven to 325 degrees F (165 degrees C). Grease and flour a 9-inch cake pan with 3-inch sides.
- Sift flour, cocoa powder, baking powder, baking soda, and cinnamon together in a bowl.
- Combine brown sugar and butter in a large bowl; beat with an electric mixer until light and fluffy. Beat in eggs one a time. Mix in vanilla extract. Beat in flour mixture in thirds, alternating with stout beer, until batter is smooth. Fold in pecans.
- Pour batter into the prepared cake pan.
- Bake in the preheated oven until a toothpick inserted into the center comes out clean, 70 to 75 minutes. Transfer cake pan to a wire rack; let cool for 20 minutes. Invert cake onto a serving platter and let cool completely.