Plan Ahead! The cookie dough needs to chill overnight.
For the Cookies:
Combine 1/4 cup buttermilk and baking soda in a small bowl. Set aside until step 5.
In a stand mixer, cream together the butter and sugar.
Add eggs, salt, vanilla and eggnog. Mix well.
Add 3 cups of flour, cinnamon, nutmeg, and baking powder. Blend until combined.
Add the buttermilk/baking soda mixture and the last 3 cups of flour. Mix until the flour is completely incorporated.
Wrap the cookie dough in plastic wrap and gently press it into a disc. Be sure it is wrapped tightly and refrigerate the dough overnight.
When you're ready to roll out the dough, preheat the oven to 350 degrees.
Sprinkle a pastry mat with flour. Divide the dough in half and roll out one-half of the dough, sprinkling flour on top of the dough as needed.
Cut out the dough in the shapes you'd like. Place the cookies on a nonstick baking mat.
Bake the cookies at 350 degrees for 9-10 minutes, removing them before they are browned.
Repeat with remaining dough, rerolling as needed.
Allow the cookies to cool, then frost them with eggnog frosting and sprinkles, if desired.
Store in an airtight container.
For the Frosting:
In a stand mixer bowl, with the mixer on medium speed, whip the butter for 2 minutes until it is almost white in color.
Add in the powdered sugar, vanilla, cinnamon, nutmeg and 3 tablespoons of eggnog.
Beat on low speed for 3-5 minutes, adding in the last 1-2 tablespoons of eggnog if the buttercream needs to be thinner.
To Decorate the Cookies:
Use a knife to spread frosting on the cooled cookies, or use a large Wilton cake decorating tip (1M or 2D work great!) to make a pretty swirl.
To decorate, sprinkle nutmeg on the top of the cookies.
Store in a single layer in an airtight container.
The calories shown are based on the recipe making 48 cookies and using all of the frosting, with 1 serving being 1 frosted cookie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.***The exact amount of cookies you get will depend on the size of the cookie cutter you use.