To make the filling:
Beat the cream cheese, sugar, egg yolk and salt until smooth.
Stir in the chocolate chips. Set aside.
To make the cupcakes:
Preheat the oven to 350F.
Whisk together the flour, sugar, cocoa, baking powder and salt in a large bowl until well mixed.
Add the milk, oil, vinegar and vanilla in another bowl, and whisk until well blended.
Pour the liquid mixture into the flour mixture, and stir until just moistened and incorporated.
Fill the paper-lined muffin cups 1/3 full with the batter.
Spoon one level tablespoon filling into the center of each cupcake.
Fill the muffin cups with more batter to make about 2/3 full.
Bake 20 to 25 minutes or until a wooden stick inserted in the batter part comes out clean.
Remove from pan and cool completely.
To make the frosting:
Add the cream cheese, butter, lemon juice, lemon zest, and vanilla in a large bowl with an electric mixture until smooth and fluffy.
Beat in the powdered sugar until creamy and well blended.
Add more powdered sugar or juice as needed for the desired consistency.
If you want to make part of the frosting into chocolate-mocha frosting, just simply mix some sifted cocoa powder and instand coffee powder into the frosting, and stir until smooth. Adding 1 to 2 or more teaspoons of cocoa and coffee powder each time, depending on how strong you want.
When the cupcakes are completely cool. Frost the cupcakes with both lemon cream cheese frosting and chocolate-mocha frosting to make white and black cupcakes.
Decorate the cupcakes into different Halloween characters with Halloween candies, decorating sugar, coconut flakes, licorice or anything you prefer to use.
Let the cupcakes set completely at room temperature, a few hours or overnight.
We froze most of our decorated Halloween cupcakes, and every time when we want one or two, just simply defrost the cupcakes in the microwave for 30 to 40 seconds.
If you want to make more than 12, just double or tripple the amount of ingredient.
Enjoy these super delicious cupcakes.
