In a large stand mixer, beat together 1 cup unsalted butter and 1 cup granulated sugar on medium speed until pale and fluffy, about 3 minutes.

Mix in 1 large egg, 1 tsp vanilla extract, and 1/2 tsp almond extract until well combined.

In a separate bowl, whisk together 2.5 cups all-purpose flour, 1 tsp baking powder, and 1/4 tsp salt. Gradually add to the wet mixture, mixing until a dough forms. If desired, fold in 1/4 cup crushed conversation heart candies for extra texture.

Wrap the dough in plastic and refrigerate for at least 2 hours to prevent spreading.

Preheat oven to 350°F. On a lightly floured surface, roll dough to 1/4 inch thickness. Cut out heart shapes using a cookie cutter. Place on parchment-lined baking sheets.

Bake for 8-10 minutes until set but not browned. Cool on a wire rack.

Whisk together 3 cups confectioners sugar, 2 tbsp meringue powder, and 4-6 tbsp water until smooth and at a 15-second consistency. Divide into bowls and tint with gel food coloring to desired pastel shades.

Pipe a border around each cooled cookie with icing, then flood the center. Let set for 15-30 minutes. Use a fine tip or marker to pipe custom messages. Top with whole conversation heart candies if desired.