Some notes:
1. I found the cake batter recipe to be a bit small and I could only make 12 cupcakes rather than the 24 that the recipe claims. I doubled the cake recipe and still had enough filling and glaze for the two batches.
2. You can easily substitute cream cheese for the mascarpone.
Ingredient lists
For the filling:
8 oz. mascarpone cheese
1/2 c. powdered sugar
1 large egg
pinch of salt
1 tsp vanilla
1 c. mini chocolate chips
For the cake batter:
1 1/2 c. flour
1/2 c. packed brown sugar
1/2 c. sugar
1/4 c. cocoa powder
1 tsp baking soda
1/4 tsp salt
1 c. boiling water
1/3 c. vegetable oil
1 Tbs apple cider vinegar
1 tsp vanilla
For the chocolate glaze:
8 oz. semisweet chocolate, finely chopped
3/4 c. unsalted butter, cut into 6 pieces
1/4 c. light corn syrup
1 tsp vanilla
Directions
Preheat oven to 350 degrees. Line two 12-cup cupcake tins with liners
For the filling: In a medium bowl, cream together the mascarpone, powdered sugar, egg, salt, and vanilla until smooth and creamy. Stir in chocolate chips.
For the the cake batter: In a large bowl, whisk together the flour, brown sugar, sugar, cocoa powder, baking soda, and salt. In a 2-cup measuring cup, combine boiling water, oil, vinegar, and vanilla. Make a well in the center of the dry ingredients and pour in the liquid ingredients. Stir together until smooth.
Fill each cupcake cup one-fourth full of batter and top with a heaping tablespoon or so of the filling; divide it evenly and use it all. Top the filling with the remaining batter, dividing it evenly. Bake until cupcakes are puffed and firm, about 25 to 28 minutes.
Meanwhile, make the glaze. Combine all the ingredients in a microwave-safe bowl and microwave on high for 1 minute. Remove from the microwave and stir until smooth. If the chocolate isn't completely melted, continue to microwave for 30-second intervals and stir until smooth.
Transfer the cupcakes to a wire rack and let cool completely. When cool, dip the top of each cupcake in the chocolate glaze. Let the excess drip from the cupcakes for a few seconds and then place the cupcake right-side up on the wire rack until the glaze firms up before serving.


