Mix the flour, baking powder, vanilla and salt. Using a peeler, peel the rinds of the well washed oranges and cut it into thin strips.
Beat the eggs with a mixer, add the orange zest, then the sugar, milk and cold margarine, beat with a mixer. Now add the flour mixture, stir by hand with a spatula.
Put the batter in a pastry bag and spray out rosettes into a tray covered with baking paper. Bake in a preheated 320°F (160 °C) oven until slightly pink, sprinkle with powdered sugar.