Chocolate-Stout Upside-Down Pineapple Cake

Ingredients

• For the pineapple layer:
• 1 stick unsalted butter, melted
• 1 cup packed dark brown sugar
• 1 large pineapple, peeled and cored or 1 pound fresh pineapple spears
• For the chocolate-stout cake:
• 2 cups chocolate stout or regular stout
• 2 sticks unsalted butter
• 1/3 cup natural cocoa powder
• 2 cups all-purpose flour
• 2 cups packed dark brown sugar
• 1 teaspoon baking powder
• 1 teaspoon salt
• 1 teaspoon baking soda
• 1/2 cup buttermilk, at room temperature
• 3 large eggs, at room temperature, lightly beaten
• 2 teaspoons pure vanilla extract

Directions

1. Set an oven rack in the center position and heat the oven to 350 degrees F. Cut the pineapple into 18 spears, each 4- by 1/2-inches. If you’re starting with fresh pineapple spears, trim them to roughly those dimensions.
2. Pour the melted butter into a 13- by 9-inch baking pan, tipping the pan so the bottom is coated. Use a pastry brush to bring a little of that butter up the sides of the pan. Scatter the brown sugar evenly over the butter, then lay the spears into 2 parallel rows.
3. Pour the stout into a small saucepan and bring it to a boil over medium-high heat, stirring from time to time so it doesn’t bubble over. Cook for 10 to 12 minutes, until only 1 cup remains. Lower the heat to medium, then stir in the butter and cocoa powder. Cook, stirring, until the mixture is smooth and unified.
4. In a large bowl, whisk together the flour, brown sugar, baking powder, and salt. Whisk the stout mixture into the flour mixture.
5. Stir the baking soda into the buttermilk until it fully dissolves, then whisk it into the batter. Whisk in the eggs and vanilla. Scrape the batter into the prepared pan, spreading it evenly over the pineapple. Bake for about 35 to 45 minutes, until a tester inserted in the center comes out clean.
6. Move the cake to a cooling rack and let it cool for 10 minutes. Turn the cake directly out onto the rack, then let it cool to room temperature, about 1 hour. Serve.