Crack eggs into a mixing bowl.
Add sugar and vanilla sugar to the same bowl and mix with a hand mixer.
Melt the butter in a pot. Once it's liquid, add the sour cream and mix together until in becomes one mass.
Add the butter-sour cream mixture to the egg-sugar mixture. Blend with a mixer.
In a separate mixing bowl add flour, baking powder and cocoa powder. Mix with a spoon.
Preheat your oven to 180 degree celcius.
Melt the chocolate and add it to the batter. Mix well.
Take your cupcake tray and put in the cupcake liners.
Fill the cupcake tray with the batter. Fill 2/3 of batter in each spot.
Bake in the oven for about 20 minutes.
While the cupcakes are baking prepare the buttercream frosting. Take a mixing bowl and add room-temperature butter. Whisk it well.
Add the powdered sugar and mix it again.
Add vanilla extract and heavy cream. Now blend it with a hand mixer until you reach the frosting consistency.
Separate the frosting into two separate bowls and add red food dye to one of them. Mix the dye into the batter.
Remove the cupcakes from the oven and let them cool down.
Before adding the frosting I like to cut the tops of the cupcakes a little. For me, that way the cream stays on the top better.
Use the frosting bags to put the buttercream frosting on the baked cupcakes. 6 cupcakes with the red frosting and 6 with the white one.
Add little splashes of red food dye on the 6 cupcakes with the white frosting.
Sprinkle all the cupcakes with some sugar sprinkles. Enjoy!