In the bowl of your stand mixer, cream the softened butter and granulated sugar on medium-high speed for exactly 3 minutes until visibly lighter in color and fluffy.

Scrape down the sides of the bowl. Add the egg and clear vanilla extract, mixing on medium speed until thoroughly combined.

Whisk together the all-purpose flour, baking powder, and salt. Gradually add to the wet ingredients in three batches, mixing on low speed just until the flour disappears to avoid overmixing.

Divide the dough into two equal portions. Place one portion between two sheets of unbleached baking parchment and roll to an exact 1/4-inch thickness.

Refrigerate the rolled dough on a baking sheet for 45 minutes to solidify the butter. Remove the top parchment and use heart-shaped cookie cutters to punch out the cookies.

Preheat oven to 350°F (175°C). Transfer cutouts to fresh unbleached baking parchment on a heavy-duty pan. Bake for 9-11 minutes until you see pale golden baked edges, leaving the centers slightly puffy. Cool completely on a wire rack.

In a clean bowl, combine sifted powdered sugar and meringue powder. Add 1/4 cup warm water and beat on medium-low for 3-5 minutes until thick and stark white. Slowly add remaining water until a knife line disappears in 10-12 seconds.

Divide the icing in half. Leave one half stark white. Tint the second half with a drop of pale pink gel food coloring. Transfer both to piping bags.

Outline and flood half the cookies with pale pink royal icing, and the other half with white royal icing. Immediately apply generous dustings of tiny red, pink, and white round sugar sprinkles so they cling to the wet icing. Allow to dry for 8 hours.