Cookie Dagger

In large bowl, beat butter with granulated sugar until fluffy. Beat in egg yolk and vanilla. In separate bowl, whisk together flour, baking powder and salt. Stir into butter mixture. Press into disc; wrap in plastic wrap. Refrigerate until cold, I hour. (Make-ahead: Refrigerate up to 24 hours.)

Between 2 sheets of waxed paper, roll out dough to 1/4-inch (5 mm) thickness. Using knife, cut out dagger shape; reserve remaining dough for other cookies. Using long spatula, place dagger on parchment paper-lined or greased rimless baking sheet.

Bake in centre of 375°F (190°C) oven until light golden on bottom and edges, about 10 minutes. Let cool on pan on rack. Transfer to rack and let cool completely. (Make-ahead: Store in airtight container for up to 4 days.)

In bowl, stir icing sugar with 2 tbsp (25 mL) water, adding more water if necessary to make spreadable. Brush over dagger; reserve remainder for another use. Decorate as desired with red candies, silver drag?, and silver flakes (if using). Let dry. (Make-ahead: Store in airtight container for up to I day.)