Mix the flour with the baking powder, sugar and vanilla sugar. Add the milk, flavor and butter and knead into a firm, smooth dough. This works particularly well with the food processor. If the dough sticks too much, chill briefly.
Shape the dough into rolls (about 1-2 cm in diameter), wrap in foil and put in the refrigerator for 2-3 hours.
Preheat the oven (top / bottom heat) to approx. 180 ° C.
Cut the cold rolls of dough into 1/2 cm thick slices with a knife and place on a baking sheet (with baking paper). Push in 2 buttonholes with the end of a wooden skewer (you can push it through).
Bake in the hot oven for about 10 minutes. Let cool down.
Melt the couverture and mix it with the oil. Brush the edge of the buttons with the chocolate and sprinkle with the sugar sprinkles.