In a medium-sized mixing bowl or bowl of a stand mixer, mix together sugar, cake flour, baking powder, baking soda, and salt.
Add the vanilla bean sugar and mix until well combined.
Add butter and mix on medium-low speed for three minutes. Because there is so little butter, you'll end up with a very fine crumb texture.
In a small mixing bowl, whisk together eggs, sour cream, oil, and vanilla extract until smooth.
Add the egg mixture to the flour mixture and beat on medium speed until just combined.
Slowly add milk and mix on low speed until just combined. The batter will be liquid. (Don't worry, you didn't do anything wrong. It's supposed to be that way.)
Fill cupcake liners just over 1/2 full.
Bake for 14 minutes and then test to see if they are done. They are done when a toothpick comes out without wet batter stuck to it. The cupcakes should appear white with specks of vanilla bean. They should not turn a golden brown. If they are not done, test again in two minutes. If they are still not done, test again in another two minutes.
When the cupcakes are done, remove them immediately from the tins and leave them on a cooling rack (or just on your counter if you don't own a cooling rack) to cool.
Carefully slice the tops off of the cooled cupcakes so they have a flat top and you've removed a thin disc of cake.
Pipe sweetened Chantilly cream onto the centers of the now flat cupcake tops.
Cut the thin cake discs in half and place each half upright into the whipped cream on each cupcake so they look like wings.
Pipe or dollop a small circle of jam into the center of each pair of wings.
Dust with confectioners' sugar.
For a variation, core a hole in each cupcake and fill with jam before before piping on the Chantilly cream.If you aren't eating within a few hours, store in the refrigerator and bring to room temperature before serving. Fairy cakes will last three to four days in the fridge.