1. In the bowl of your mixer, fitted with cookie paddles or with the paddle attachment, mix the flour and powdered sugar to combine. 
2. Add the softened butter to the dry mixture. Mix on low speed until no visible chunks of butter remain.  You want to achieve a sandy texture.
3. Next, add the vanilla extract and the egg. Mix on low speed. The dough should not come together completely into a ball.
4. Turn the dough out onto a clean surface and knead it together into a ball.  Then wrap the dough in plastic wrap and place in the fridge for 1 hour or 15 min in the freezer. 
5. Preheat the oven to 350°F (180°C)
6. Now that the dough is chilled, roll it out to 1/ 8 inch (4 mm) thick. (Note: Roll out on a sheet of baking parchment to avoid adding too much flour. Adding too much flour can change the texture of the dough.)
7. Use a gingerbread man cookie cutter upside down to make reindeer.
8. Bake for 12 minutes until lightly golden then transfer to a cooling rack to cool completely. They will firm up.

Decorate:

1. Place chocolate chips in a microwave proof bowl and microwave for 20 seconds at a time, stirring after each time. Once chocolate is looking almost melted, don't microwave it again, just stir the chocolate until it is completely smooth.
2. Place melted chocolate into an icing bottle or piping bag to pipe the antlers, ears, and eyes. You can also use a small zip-top freezer bag and snip off the corner for piping.
3. Attach a red sugar pearl to the melted chocolate to form the nose.
4. Place the cookies in the fridge for 5 minutes to let the chocolate harden.
5. Enjoy!