I found both this recipe and the cheesecake recipe below at the same time, and I couldn't resist making them together-- they're like inverses of each other! I called them secret agent desserts because they'd infiltrated one another--cake (okay, brownie) hiding in the cheesecake, and cheesecake sneakily nestled in the middle of each cupcake.
When smitten kitchen made these, she (and several commenters) had a hard time keeping the filling in the middle. I used an ice-cream scoop that held about two tablespoons and put two scoops of cupcake batter, then two of filling, and then another one and a half of batter, making sure that no filling was peeking out of the top, and that seemed to work just fine.
I would suggest using liners for these, as I didn't and they were a bit tricky to get out of the tray. They didn't puff up too much, but they were moist and crumby and amazing.
The Great Book of Chocolate, David Lebovitz
Yield: 12 cupcakes
8 ounces cream cheese (room temperature)
1/3 cup granulated sugar
1 large egg (room temperature)
2 ounces bittersweet or semisweet chocolate, coarsely chopped
1 1/2 cups all-purpose flour
1 cup firmly packed light brown sugar
5 tablespoons natural unsweetened cocoa powder (not Dutch-process)
1 teaspoon baking soda
1/4 teaspoon salt
1 cup water
1/3 cup vegetable oil (canola, not olive)
1 tablespoon white or cider vinegar
1 teaspoon vanilla extract
Make the filling: Beat together the cream cheese, granulated sugar, and egg until smooth. Stir in the chopped chocolate pieces. Set aside.
1. Adjust the rack to the center of the oven and preheat to 350°F. Butter/spray a 12-cup muffin tin, or line the tin with paper muffin cups.
2. In a medium bowl sift together the flour, brown sugar, cocoa powder, baking soda, and salt. In a separate bowl, mix together the water, oil, vinegar, and vanilla.
3. Make a well in the center of the dry ingredients and stir in the wet ingredients, stirring until just smooth. Stir any longer and you will over mix the batter and end up with less-than-tender cupcakes.
4. Divide the batter among the muffin cups. Spoon a few tablespoons (2-4) of the filling into the center of each cupcake, dividing the filling evenly. (If you do it this way, the cupcakes will have a marbled look on top, or be cheesecake-topped. If you want surprise filling, save some cupcake batter to put over the filling, making sure that no filling peeks out.
5. Bake for 25 minutes, or until the tops are slightly golden brown (if they're cheesecake-topped) and the cupcakes feel springy when gently pressed. These keep well unrefrigerated for 2 to 3 days if stored in an airtight container. I thought about buying one of those cupcake-transporters (finally, a way to justify it!) but we, um, ate them all before I could get to the store.