Simple sugar cookies serve as the canvas for these elegant "cherry blossoms." Use pink royal icing to create the "petals" and brown luster dust to form the "branches."
Sugar Cookies: In a medium bowl, whisk together flour, salt, and baking powder. In the bowl of an electric mixer fitted with the paddle attachment, beat together butter and granulated sugar on medium-high speed until light and fluffy. Add vanilla, egg, and brandy and continue beating until well combined. Reduce speed to low and add flour mixture, beating until just combined. Shape dough into a disk, wrap in plastic, and refrigerate until firm, at least 45 minutes and up to overnight.
Preheat oven to 350 degrees. Line two baking sheets with parchment. On a lightly floured surface, roll out dough to 1/4 inch thick. Use a 2 5/8-inch square cutter to cut out squares. Reroll scraps once (you should have about 16 cookies). Transfer to prepared sheets, spaced about 1 inch apart. Refrigerate at least 1 hour. Bake until set and golden around edges, 15 to 20 minutes. Transfer sheets to wire racks and let cool completely.
Royal Icing: In the bowl of an electric mixer fitted with the paddle attachment, beat egg whites on medium speed until frothy. Reduce speed to low and add confectioners' sugar, 1/4 cup at a time, increasing speed to medium-high between each addition, until mixture has consistency of shampoo. Add lemon juice. Tint with pink food color until desired shade is reached. Transfer mixture to a shallow bowl. If not using immediately, icing can be stored at room temperature, with plastic wrap pressed directly on surface, up to 2 days, or in refrigerator, well wrapped in plastic, up to 3 days. Bring to room temperature before using.
Working with one cookie at a time, dip cookie top-side down in icing to completely coat surface, allowing excess glaze to drip back into bowl. Invert cookie and clean edges with your finger, if desired. Transfer to a wire rack or baking sheet and let stand at room temperature until completely dry, at least 12 hours and up to overnight. Reserve remaining icing for decorations, at room temperature, with plastic wrap pressed directly on surface, or in refrigerator, well wrapped in plastic. Bring to room temperature before using.
Stir additional confectioners' sugar into icing until it has consistency of toothpaste. Divide mixture into 3 portions and tint with pink food color until 3 desired shades are reached. Transfer each color to a piping bag fitted with a small plain round or star tip (such as Ateco #2, #3, or #13).
Place luster dust in a small bowl. Stir in vodka, a little at a time, until mixture has consistency of thick watercolor paint. Using a small food-safe paintbrush, paint a tree branch design on surface of each cookie. Using the 3 shades of pink icing, pipe small blossoms on branches. Let stand at room temperature until completely dry, about 4 hours. Cookies can be stored in an airtight container at room temperature up to 3 days.