Preheat oven to 400° F. Line baking sheets with parchment paper and set aside.

In a bowl, whisk together the flour, baking powder, salt. Set aside.

With mixer on low, slowly add flour mixture to the bowl. The dough is ready when most of it sticks to the paddle. When touched, it has a little give, but does not stick to fingers. If it's too sticky, add more flour, 1 tablespoon at a time.

Flour the work surface and roll dough to about 1/4-inch thick, using flour for dusting as necessary. Use a 2 ½ to 3 inch heart-shaped cookie cutter to cut cookies and place on prepared baking sheet. Gather scraps and re-roll dough when necessary. If baking in a warmer climate, chill cookies for 20 minutes before baking.

Bake for 7 to 8 minutes, rotating halfway through. Allow cookies to cool on baking sheet for 2 minutes, then transfer to wire rack to cool completely. Prepare icing.

Place the meringue powder and 5 tablespoons water in a large mixing bowl, and whip with the whisk attachment until foamy, about 3 minutes.

Add the vanilla and confectioners' sugar, then whip on medium speed until thick, about 3 minutes. The royal icing should hold a medium soft peak. If necessary, thin with additional water, a few drops at a time, to get the desired consistency.

Divide the icing into two bowls. Add red food gel to one bowl and pink food gel to the second bowl. Transfer to two separate icing bags, each fitted with a small round tip (I used Wilton #2).

Outline half the cooled heart cookies with the pink icing. Fill with icing, then let them dry completely. Repeat with red icing and the remaining cookies. Let the cookies dry completely This can take a couple hours. Keep remaining icing for decorating.

After the icing is dry, use the remaining icing to add designs on top. Dry completely.