Add the softened butter and granulated sugar to a large bowl. Beat on medium speed for 2–3 minutes until smooth and creamy but not fluffy. Scrape the bowl well.
Add the egg, vanilla extract, and almond extract. Mix just until fully combined and smooth.
In a separate bowl, mix the flour, baking powder, and salt. Add this dry mixture to the butter mixture in two additions, mixing on low speed until a soft, smooth dough forms. The dough should not be sticky.
Divide the dough into two portions. Place each portion between two sheets of parchment paper and roll to an even thickness of about 6 mm. Stack on a flat tray and chill in the refrigerator for at least 1 hour until firm.
Preheat the oven to 170°C. Line baking trays with parchment paper.
Cut heart shapes using a sharp heart-shaped cutter. Place cookies on the prepared trays, spacing them slightly apart. Chill the cut cookies for 10 minutes to help them keep sharp edges.
Bake for 10–12 minutes, just until the tops look set and the edges remain pale. Do not allow browning.
Cool the cookies completely on the tray for 5 minutes, then transfer to a wire rack. Cookies must be fully cooled before icing.
In a bowl, mix powdered sugar and meringue powder. Add 5 tablespoons water and vanilla extract. Beat on low speed, then medium, until thick and smooth.
Divide icing into separate bowls. Tint with pink, burgundy, cream, and green gel colors.
Adjust icing consistency:
For outlining and piping details, icing should be thick and hold soft peaks.
For flooding, thin the icing with a few drops of water until it flows smoothly and settles flat in about 10 seconds.
Pipe an outline around each cookie using matching icing color. Immediately flood the center and gently tap the cookie to smooth the surface. Let set for 1–2 hours until fully dry to the touch.
Using thick pink icing, pipe a neat crisscross lattice pattern on the burgundy hearts. Keep lines even and lightly raised.
Pipe small floral details using pink icing, then add tiny green leaves for contrast. Work slowly for clean, precise designs.
Allow the decorated cookies to dry uncovered at room temperature for at least 6–8 hours, or overnight, until the icing is completely firm.
