Preheat the oven to 375 degrees. Line a cookie sheet with parchment paper or silicone mat.
In a medium bowl, mix together the flour, baking soda, cream of tartar, nutmeg, and salt. Set that aside.
In a small bowl, mix together 1 tablespoon of cinnamon with ¼ cup of sugar. Mix well and set aside.
In the bowl of a stand mixer fitted with the paddle attachment or a large bowl with a hand mixer, add the sugar and butter. Mix well until the butter and sugar are well combined.
Add the eggnog, eggs, and vanilla extract to the stand mixer. Mix again on low speed until fully combined. Scrape the sides of the bowl if necessary.
Add the dry ingredients to the wet ingredients in the stand mixer and mix until fully combined.
With an ice cream scoop, scoop the cookie dough balls into the cinnamon and sugar mixture. Roll the dough in the cinnamon and sugar mixture. Place the dough ball on the prepared baking sheet. Continue until the baking sheet is full.
Bake cookies for 9-11 minutes or until the cookies are slightly brown and soft. For best results, allow the cookies to cool on a wire rack.