Preheat your oven to 350°F (175°C). In a large bowl, whisk together flour, baking powder, and salt. In a separate bowl, cream butter and sugar until light and fluffy. Add egg and vanilla extract, then gradually mix in dry ingredients.

Cover the dough with plastic wrap and refrigerate for at least 1 hour to maintain shape during baking.

Sprinkle work surface with flour, roll out dough to about ¼ inch thickness, and cut shapes with a watermelon slice cookie cutter. Place cookies on parchment-lined baking sheet.

Bake for 8-10 minutes or until edges are lightly golden. Let cool before transferring to a wire rack.

Prepare royal icing by mixing meringue powder with powdered sugar and water to reach piping consistency. Tint with gel food coloring for a vibrant pink.

Decorate cooled cookies by piping a border with pink icing and filling in centers. Place chocolate chips for seeds while icing is wet.

Let decorated cookies dry uncovered for at least 6 hours or overnight for a smooth finish.