1. Whisk flour, baking powder, and salt in a medium bowl and set aside. In a large bowl, beat sugar and butter with an electric mixer on medium until light and fluffy, about 3 minutes.
2. Add egg and vanilla and continue to beat until incorporated, about 30 seconds. Reduce speed to low, add flour mixture, and mix until just combined, about 30 seconds.
3. Divide dough in half and form each half into a 5 inch-wide disc; wrap in plastic and refrigerate until firm, at least 1 hour and up to 2 days.
4. Center a rack in the oven and heat to 350 degrees. On a lightly floured counter, roll one disc of dough into a sheet about 1/8 inch thick. With a cookie cutter, cut dough and transfer cookies to a parchment-lined baking sheet, spaced about 1/2 inch apart.
5. Bake until edges are lightly browned and centers feel set when gently pressed, 8 to 10 minutes. Transfer cookies to a wire rack and let baking sheet cool completely before repeating with remaining dough.
6. To make royal icing, beat confectioners' sugar and egg whites in a large bowl with an electric mixer on medium-low until combined, about 1 minute. Increase speed to medium-high and continue to beat until glossy, stiff peaks form, 4 to 5 minutes. Transfer to a piping bag fitted with a thin tip and decorate cooled cookies. Let icing dry completely before serving.
Source: Hannaford fresh Magazine, November - December 2017