Preheat the oven to 350°F. Line two baking sheets with parchment paper and set aside.
In the large bowl of an electric stand mixer, beat butter, sugar, and brown sugar on medium until fluffy. Mix in egg and vanilla until all is combined.
In a separate bowl, combine flour, cinnamon, baking soda, salt, baking powder and nutmeg. Slowly add to the butter mixture. Change the electric stand mixer from medium to low and gently stir in oats until everything is blended.
Remove dough from the bowl and shape into small, consistent balls (Using an ice cream scoop is a great way to ensure all cookies come out uniform). Place on a prepared baking sheet and bake for 8-10 minutes.
While cookies are baking, microwave the three bowls of chocolate candies until completely melted, 30-40 seconds.
Remove cookies from the oven and let cool on a baking sheet for 5 minutes. Alternate dipping half of the cookie between red, white, and green until your batch of cookies is completed. Sprinkle peppermint candies on top of chocolate before it cools. Let cool for an additional 5-10 minutes.
