Prepare the dough: combine the flour, baking powder, vanillina, a pinch of salt, 2 tablespoons of granulated sugar, and 1 packet of the vanilla powdered sugar. Cut the cold butter into pieces and add it to the flour along with the egg. Knead until the dough detaches from the bowl. Roll it out thinly on a floured work surface; cut out the cookies with a cookie cutter and bake for 15-20 minutes at 320°F. Remove from the oven, let cool, and dust with the other packet of vanilla powdered sugar.