In a medium bowl, whisk together flour, baking powder, and salt until well combined. Set aside.
In a large mixing bowl, cream together softened butter and sugar using an electric mixer on medium speed for 2-3 minutes until light and fluffy.
Add the egg, vanilla extract, and almond extract (if using) to the butter mixture. Beat until fully incorporated, about 1 minute.
Gradually add the flour mixture to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.
Divide the dough in half and flatten each portion into a disc shape about 1-inch thick. Wrap tightly in plastic wrap and refrigerate for at least 1 hour or up to 3 days.
Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
Working with one disc at a time, roll the dough on a lightly floured surface to about ¼-inch thickness.
Use a snowman-shaped cookie cutter to cut out shapes. Place cut cookies on the prepared baking sheets, spacing them about 1.5 inches apart.
Bake cookies in the preheated oven for 10-12 minutes, or until the edges are just barely beginning to turn golden.
Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.
In a large bowl, combine powdered sugar and meringue powder. Add 5 tablespoons of warm water and vanilla extract, then beat with an electric mixer on medium-high speed for 5-7 minutes, until stiff peaks form.
Divide the icing into portions for different colors: the largest portion for white (snowman base), and smaller amounts for black (eyes/buttons), orange (nose), and red (scarf). Cover any icing not in use with a damp paper towel to prevent crusting.
Transfer each icing color to separate piping bags fitted with small round tips.
Begin by outlining and flooding each cookie with white icing for the snowman base. Let this layer dry for 30 minutes before adding details.
Use black icing or an edible marker to add eyes and buttons. Pipe orange icing in a small triangle shape for the carrot nose. Add scarves using red icing in swooping lines across the "neck" of your snowman.
Allow decorated cookies to dry completely for at least 4 hours, preferably overnight, before stacking or packaging.