Preheat oven to 350 ̊.
In a large mixing bowl, combine melted butter, brown sugar, and sugar. Add egg, egg yolk, and vanilla. Beat well.
Mix in flour, salt, and baking soda until uniform.
Finally, fold in chocolate chips.
Scoop dough into a lined cupcake pan.
Bake for 20 minutes or until golden brown. Allow to cool.
Melt white chocolate chips, then drizzle over cupcakes.
Top them off with sprinkles of your choice.
Refrigerate for 10 minutes to allow chocolate to harden.