Tasty Chocolate Cheese Muffins

I also like to use the chocolate batter frequently (without the filling), sometimes to whip up a last-minute siyum treat (yes, my kids also show me that note after 9 p.m. the night before).
With no eggs in the batter, these are great chocolate cupcakes for anyone with an egg allergy.
 
PAREVE OPTION:
To make pareve muffins, substitute the milk for water only and skip the cheese filling. This recipe doubles well, too.
 
For the cheese filling
2 eggs, at room temperature
1 cup sugar
2 (8-ounce) bars cream cheese (not whipped), at room temperature
 
For the batter
3 ½ cups flour
¾ cup cocoa powder (preferably Dutch process)
2 teaspoons baking soda
2 ¼ cups sugar
1 teaspoon salt
1 ¼ cups whole milk
1 cup cold water
¾ cup oil
1 tablespoon pure vanilla extract
5 teaspoons balsamic vinegar
 
For the topping
¾ cup chocolate chips
1 (3.5-ounce) bar white chocolate (I use Choco Blanc), chopped into small bits
 

1. Preheat oven to 350°F. Line two muffin pans with paper liners.
2. Prepare the cheese filling: In the bowl of a stand mixer, on medium speed, beat together eggs, sugar, and cream cheese until smooth, about 2 minutes. Transfer filling to a piping bag fitted with a wide-rimmed piping tip. Set aside.
3. Prepare the batter: In the bowl of a stand mixer fitted with the whisk attachment, on low speed, stir together flour, cocoa powder, baking soda, sugar, and salt until evenly blended. Slowly add milk, water, oil, vanilla, and vinegar, stirring until the batter is smooth. Scrape down the sides as needed, mixing until well combined.
4. Transfer batter to a large reseal-able bag; snip off one corner. Pipe batter into prepared muffin tins, filling each cup half full. Then, press the cheese filling piping tip slightly into the batter; squeeze into the batter. The chocolate batter will rise a bit as the filling goes in.
5. Sprinkle the top of each muffin with chocolate chips and chopped white chocolate.
6. Bake muffins until a toothpick inserted into the center of a muffin comes out clean, 26-28 minutes.

Yield: about 24 muffins
 
NOTE: Why is there vinegar in the muffin batter? Baking soda, the ingredient that makes these muffins rise, starts to work only when it comes in contact with an acidic ingredient. Some common types used in baking are lemon juice, buttermilk, and vinegar. Sweet balsamic vinegar, which has a flavor that goes well with the rich flavor of cocoa, is added to the batter here to give these muffins a deep, full flavor. Don’t you worry, though, the muffins won’t taste anything like vinegar once baked.