Cream butter, brown sugar, and sugar until fluffy and light in color. Add eggs, molasses, and vanilla and mix together.
Add in dry ingredients and mix together until batter just comes together. Chill 2 hours to overnight to let flavors meld together.
Separate dough into 3 sections. Roll out eat section to 1/4" between 2 sheets of parchment paper cut to fit baking sheets.
Cut out shapes with cookie cutters. Place cookies on baking sheet and chill in fridge for 5-10 minutes.
BAKE
Pre-heat oven to 350°
Bake cookies for about 12 minutes. Take out and let them sit on cookie sheet another 2-4 minutes and they will crisp up on the cookie sheet.
If your going to re-roll any scraps, you will need to follow the same process: re-roll scraps between parchment paper, chill for at least 1 hour, cut shapes and chill again for 5-10 minutes before baking.
Let cookies cool and frost with royal icing. Store in sealed container on counter 2-3 days or in freezer up to 6 months.
ROYAL ICING
Place egg whites and cream of tarter in mixer with the whisk attachment and beat for 2-3 minutes
In a metal bowl over a pot of simmering water place water and sprinkle in the gelatin over the water and let it sit for 2 minutes. Stir in sugar and cook for 5-7 minutes or until sugar is fully dissolved.
Add the sugar mixture to the mixer. Add powdered sugar into the egg whites and beat on medium high speed for another 10-12 minutes until stiff peak. Add in vanilla and white food color.
This frosting will crust fast so you need to keep covered with a wet paper towel while you decorate the cookies.