Preheat the oven to 350°F. Line 2 large baking sheets with parchment paper and set aside.

In the bowl of a stand mixer, cream the butter until smooth. Add the dark brown sugar and mix until well combined. Add in one egg, molasses, milk, and vanilla extract. Mix together until smooth.

In a separate large bowl, add the flour, ginger, baking soda, and cinnamon. Whisk together to combine.

Add the dry ingredients into the wet ingredients 1 cup at a time and mix until well combined. The dough should cleanly pull away from the mixing bowl.

Transfer the dough onto a lightly floured surface and roll out to ⅜-inch thickness (or a little less than ½-inch).

Use a pig shaped cookie cutter to cut the dough into pigs. Place the pigs 1 ½ inches apart on the prepared baking sheets.

In a small bowl, crack open the remaining egg and whisk. Brush the beaten egg over the tops of the pigs using a pastry brush.

Bake for 10 to 12 minutes, until the edges are lightly browned.