I don't know what is wrong with my chocolate stout cupcakes. The middle has sunk on all 3 batches I made; not completely baked? I've checked oven temp, tried different liners, ingredients at room temperature, rotated pans in the oven, and tried a hand mixer instead of my Artisan. There is only one other possibility I can think of. Most stout recipes call for dutch-processed cocoa. I used Ghirardelli that is a combination of natural and dutch-processed. Don't know how to adjust for combination cocoa. I typically would use Droste but my store isn't carrying it anymore. Is the cocoa the problem? Next step is to try a different recipe however this one seems to be all over the net with lots of success.
For the Guinness Chocolate Cupcakes
1 cup stout (such as Guinness)
1 cup (2 sticks) unsalted butter
3/4 cup unsweetened cocoa powder (preferably Dutch-process)
2 cups all purpose flour
2 cups sugar
1 1/2 teaspoons baking soda
3/4 teaspoon salt
2 large eggs
2/3 cup sour cream
Ganache Filling (Updated to double it, based on many commenters suggestions — thanks!)
8 ounces bittersweet chocolate
2/3 cup heavy cream
2 tablespoons butter, room temperature
1 to 2 teaspoons Irish whiskey (optional)
Baileys Frosting (see Recipe Notes)
3 to 4 cups confections sugar
1 stick (1/2 cup or 4 ounces) unsalted butter, at room temperatue
3 to 4 tablespoons Baileys (or milk, or heavy cream, or a combination thereof)
Special equipment: 1-inch round cookie cutter or an apple corer and a piping bag (though a plastic bag with the corner snipped off will also work)
Make the cupcakes: Preheat oven to 350°F. Line 24 cupcake cups with liners. Bring 1 cup stout and 1 cup butter to simmer in heavy large saucepan over medium heat. Add cocoa powder and whisk until mixture is smooth. Cool slightly.
Whisk flour, sugar, baking soda, and 3/4 teaspoon salt in large bowl to blend. Using electric mixer, beat eggs and sour cream in another large bowl to blend. Add stout-chocolate mixture to egg mixture and beat just to combine. Add flour mixture and beat briefly on slow speed. Using rubber spatula, fold batter until completely combined. Divide batter among cupcake liners, filling them 2/3 to 3/4 of the way. Bake cake until tester inserted into center comes out clean, rotating them once front to back if your oven bakes unevenly, about 17 minutes. Cool cupcakes on a rack completely.