How to make
Grate the yolks into a bowl.
Add the butter, powdered sugar, cream, vanilla and flour.
Knead a soft buttery dough.
Line a baking tray with baking paper.
Cut small balls from the dough, flatten them slightly with your hands and arrange them at a small distance from each other.
Bake the butter biscuits in a non preheated oven at 340°F (170°C), until they're done.
Remove the butter biscuits, leave them to cool and sprinkle them with powdered sugar if desired.
You guessed it, these butter biscuits with sour cream literally melt in your mouth.