This recipe elevates plain chocolate cupcakes with a layer of cheesecakelike chocolate-studded, sweetened, whipped cream cheese on top. They look impressive, taste chocolaty but not too sweet, and don’t require frosting! Pack them up and bring them to a bake sale, birthday party, potluck, or picnic.
For the topping:
12 ounces (1 1/2 [8-ounce] packages) cream cheese, at room temperature
Heat the oven to 350°F and arrange a rack in the middle. Using 2 (12-well) muffin pans, line 18 of the wells with paper liners (leave the remaining 6 empty); set aside.
For the topping:
Place the cream cheese and sugar in the bowl of a stand mixer fitted with the paddle attachment and beat on medium speed until smooth, about 1 to 2 minutes. Stop the mixer and scrape down the sides of the bowl and paddle with a rubber spatula.
Add the egg, return the mixer to medium speed, and beat until incorporated, about 1 minute. Stop the mixer and scrape down the sides of the bowl and paddle with the rubber spatula.
Turn the mixer to low speed, add the chocolate, and mix until just combined, about 20 seconds. Transfer the cream cheese mixture to a medium bowl. Wash and dry the mixer bowl and paddle attachment and return them to the stand mixer.
For the cupcakes:
Place the flour, cocoa powder, baking soda, and salt in a medium bowl and whisk to aerate and break up any lumps; set aside. Mix together the buttermilk and vanilla in a small bowl or measuring cup and set aside.
Place the sugar and oil in the mixer bowl and mix on medium speed until combined, about 1 minute. Reduce the speed to low and slowly add half of the flour mixture, mixing until just combined. Add half of the buttermilk mixture and mix until just combined. Repeat with the remaining flour and buttermilk mixtures, mixing until combined, about 2 minutes total.
Fill the prepared muffin wells about halfway with the cupcake batter. Divide the cream cheese topping among the cupcakes (about a heaping tablespoon for each). Place the muffin pans side by side in the oven and bake for 10 minutes. Rotate the pans front to back and side to side and bake until a toothpick inserted into the center of the cupcakes comes out clean, about 8 to 10 minutes more.
Place the pans on wire racks and let them cool for 15 minutes. Remove the cupcakes from the pans and cool completely on the racks before serving.