Beat the butter, sugar and vanilla until light and fluffy. Beat in the egg. Combine the flour and baking powder and fold into the butter mixture and mix well. Stir in the cherries. Chill the dough for 30 minutes. Shape into 1 ½ʺ crescents. Bake on parchment lined baking sheets at 350°F for 10 – 12 minutes. While still warm, dust with icing sugar.