Knead a soft dough from the butter, cream cheese and flour. Roll it out into a sheet.
Cut out medium-size circles from it (about the size of a tea cup saucer), sprinkle them with sugar.
Fold them in 2, with the sugary side on the inside.
Sprinkle them with sugar once again and fold down the middle.
Put a piece of walnut in the middle and fold them again to obtain a triangular shape.
Bake in a moderate 356°F (180 °C) oven about 30 min.
Sprinkle with powdered sugar and vanilla.