Eggnog Gingerbread Thumbprint Cookies

Make the Cookie Dough
2 In a large bowl, combine flour, baking soda, spices, and salt. Hand whisk to evenly distribute ingredients and set aside.
3 In the bowl of a stand mixer, (or a large bowl using a handheld mixer) beat together softened butter with brown sugar until a creamy paste is formed. 1-2 minutes.
4 Add the egg and molasses to the butter mixture. Mix on medium until smooth, scraping sides and bottom of bowl with spatula as needed.
5 Next, spoon in the flour mixture a third at a time. Mixing in between each addition until all is incorporated and a smooth cookie dough is formed. Scrape bottom and sides of the bowl as needed.
Scoop and Chill
6 Pre-measure cookie dough balls before chilling. Take a 1.5 tablespoon capacity cookie scoop and measure out dough into 1 ½ inch balls. Place the cookie balls on a parchment paper lined cookie sheet or dish, cover the dish with plastic wrap and refrigerate for 3 hours or overnight to develop flavor.
23 Scooping the dough before chilling is much easier than after the dough is cold. Chilling allows the dough to rest and the butter to firm, preventing cookies from spreading too much in the oven.
Shape and Bake
7 Preheat oven to 350℉ (180℃) and line a rimmed cookie sheet with a double layer of parchment paper. Bake in batches.
9 After cookie dough has properly chilled, roll the cookie dough balls in between the palms of your hands to pack and smooth. Place a cookie ball in the bowl of granulated sugar, gently roll to coat completely. Repeat with remaining dough balls.
10 Place dough balls on prepared baking sheet and space them 2-inches apart. One baking sheet should be able to fit 9 cookies at a time.
11 Shaping: Use a rounded 'half teaspoon' measuring spoon to gently press a perfect 'thumbprint' into your cookie dough. (only press 1/3  of the way down) **If the cookie cracks slightly roll in your hands again and then reshape.
12 Transfer baking tray to the middle rack of the oven and bake for 9-10 minutes until they are set but still soft. 
13 Don't over bake cookies until they are hard. They will firm as they cool into tender cookies, but not a crisp gingerbread.
14 Place the baking sheet on a wire cooling rack. After removing cookies from the oven, immediately take your teaspoon and gently reshape the 'thumbprint' while cookies are still warm. **Just enough pressure to adjust the shape, as the indent will disappear some when baking, since they are being baked without a filling. 
15 Let cookies cool on the cookie sheet for 5 minutes. Then, transfer cookies to a wire cooling rack to cool completely before filling with eggnog white chocolate.
Eggnog White Chocolate Filling
18 Combine the eggnog with the white chocolate chips in a microwave safe bowl. Heat for 1.5 minutes in microwave, stirring every 30 seconds until melted and smooth.(You can also use a double boiler if preferred.)
19 Transfer eggnog white chocolate to a piping bag. Pipe into thumbprint of cooled cookies.
20 Allow chocolate to set for 30 minutes to an hour after filling. You can also pop the cookies in the fridge to speed things up, just don't store them in the fridge.
21 Sprinkle with cinnamon or grated nutmeg!
22 Store cookies in an air tight container at room temperature.