Preheat oven to 350 degrees Fahrenheit. Grease 24 mini donut molds.

In a large bowl, combine sugar, flour, cocoa, baking soda, baking powder, vanilla sugar, and salt with a fork. Stir in eggs, one-fourth cup oil, and orange juice and mix well.

Pour into molds and bake for 12 minutes.

Allow to cool completely.

Remove donuts from molds. Place each kind of chocolate chips in a resealable plastic bag. Add half a teaspoon oil to each. Place bags in a bowl of boiling water and mash with a spoon until chocolate is melted.

Snip the corner of each bag and drizzle chocolate over brownies. Cover with sprinkles.