Preheat the oven to 160 degrees. In a large bowl, mix together the butter room temperature and sugar. Beat with a mixer at high speed until fluffy state. It will take about 2 minutes. Gradually add the eggs and continue mixing until the mixture becomes homogeneous.

In another bowl, combine flour, baking powder, salt and vanilla sugar. Now add to creamy mixture, half the milk, then half the flour mixture and mix again. Repeat this process.

Grate the zest and squeeze orange juice. White chocolate RUB on a small grater.

Add the orange juice, the grated zest and grated chocolate to the dough. Mix until a homogeneous mixture.

Put the dough into molds for baking cupcakes. My photo poured the batter to the top. You pour a little without adding. During baking the dough rises slightly. A few times, gently tap the form on the table to get rid of excess air bubbles. Place the baking sheet on the middle tier of the grid in the oven and bake for about 18-20 minutes. Check on a dry stick.