I recommend using a stand mixer but you can do everything by hand
In your stand mixer, cream the butter and brown sugar together. Add one egg, molasses, milk and vanilla extract. Mix until well combined
Lightly mix the dry ingredients in a separate bowl: flour, ginger, baking soda, salt, and cinnamon.
Add the dry ingredients to the wet mixture and mix until well combined and a dough has formed.
(optional) While this step is optional, I highly recommend chilling your ball of dough for at least 30 minutes in the refrigerator. It will help immensely for the next step.
Preheat the oven to 350℉
On a surface lightly dusted with flour, roll out your dough to roughly ⅜ of an inch thick. Use the pig-shaped cookie cutter to shape the cookies placing them on a baking sheet lined with parchment paper
Beat a second egg to use as egg wash. Brush the tops of the cookies with the egg wash.
Bake for 10 to 12 minutes until you reach the desired consistency
Remove from the oven and let cool!