Excellent. My cream cheese filling ended up working more like a topping, but that did not impact the taste.
FOR THE FILLING
8 ounces cream cheese, regular or reduced fat, at room temperature
1/3 cup granulated sugar
1 large egg, at room temperature
2 ounces bittersweet or semisweet chocolate, coarsely chopped, or 1/2 cup chocolate chips
FOR THE CUPCAKES
1 1/2 cups all-purpose flour
5 tablespoons natural unsweetened cocoa powder (not Dutch-process)
1 teaspoon baking soda
1/4 teaspoon salt
1 cup firmly packed light brown sugar
1 cup water
1/3 cup unflavored vegetable oil
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.
Make the cupcakes: Adjust the rack to the center of the oven and preheat to 350°F (175°C). Butter a 12-cup muffin tin, or line the tin with paper muffin cups.
In a medium bowl sift together the flour, cocoa powder, baking soda, and salt. In a separate bowl, whisk together the brown sugar, water, oil, vinegar, and vanilla. 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.
Divide the batter among the muffin cups, leaving just a couple spoonfuls behind in the bowl (if you’d like to marble the tops, as shown). Spoon a couple tablespoons of the filling into the center of each cupcake, dividing the filling evenly. Spoon any remaining chocolate batter back over the cream cheese center, if you plan to marble the tops. Use a butter knife inserted only about 1/2-inch into the cupcake to swirl the batters together decoratively. The cupcakes will be almost completely full (90%), which is fine. If you still have batter leftover, make one or two additional cupcakes.
Bake for 25 minutes, or until the tops are slightly golden brown and the cupcakes feel springy when gently pressed. These moist treats will keep well unrefrigerated for 2 to 3 days if stored in an airtight container.