In a large mixing bowl, combine softened unsalted butter and granulated sugar. Beat together on medium speed for about 3-4 minutes until light and fluffy.

Add in one egg and one teaspoon of vanilla extract. Mix on low speed until fully combined, scraping down the sides.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. Combine this dry mixture into the wet ingredients.

Divide the dough into three equal portions and color each with red, green, and brown food dyes.

Roll each colored dough portion into a log, wrap tightly in parchment paper, and chill in the refrigerator for at least 1 hour.

Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.

After chilling, unwrap the logs and slice them into rounds approximately 1/4 inch thick.

Sprinkle tops with black sesame seeds if desired. Bake in the preheated oven for 10-12 minutes until lightly golden.

Transfer cookies to cooling racks to cool for about 5 minutes before serving.