* In a large bowl, combine the cake mix, coffee, eggs and oil; beat on low speed for 30 seconds. Beat on medium for 2 minutes. Fill paper-lined muffin cups two-thirds full.
* Bake at 350° for 18-22 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely.
* Meanwhile, in a double boiler or metal bowl over simmering water, constantly stir the chocolate, sugar and 3 tablespoons coffee until smooth. Remove from the heat (mixture will be thick). Stir a small amount of hot mixture into egg yolks; return all to the bowl, stirring constantly. Cook and stir for 4-5 minutes or until mixture reaches 160°.
* Divide mixture among three small bowls. Into one bowl, stir orange juice concentrate. Stir Nutella and cream into another; stir remaining coffee into the third bowl. Fold 1/2 cup of whipped topping into each. Chill for 10 minutes.
* Cut a small hole in the corner of a pastry or plastic bag; insert a very small tip. Fill with one filling flavor. Push the tip through the bottoms of the paper liners to fill eight cupcakes. Repeat with remaining fillings and cupcakes.
* For ganache, place chocolates in separate small bowls. In a small saucepan, bring cream just to a boil. Pour 1/2 cup cream over bittersweet chocolate; pour remaining cream over white chocolate. Whisk chocolate mixtures until smooth.
* Stir 2 teaspoons corn syrup into bittersweet ganache and 1/2 teaspoon corn syrup into white ganache. Cool, stirring occasionally, to room temperature or until ganache thickens slightly, about 10 minutes.
* Dip tops of cupcakes in bittersweet ganache. Tint white ganache as desired; pipe designs over tops. Refrigerate until set. Store in an airtight container in the refrigerator. Yield: 2 dozen.