Preheat the oven to 375°F and line 2 baking sheets with parchment paper.

Add the butter, brown and white sugars to a large mixing bowl.  Use either a handheld mixer or a stand mixer. If you have a standing mixer then use the paddle attachment. 

Beat the butter and the sugars at medium-high speed until light and fluffy—about 3-minutes. Reduce the speed to medium-low and add the egg yolk and vanilla. Increase the speed to medium and beat until blended—about 20-30 seconds.

Reduce speed to medium-low and add molasses. Beat until incorporated, about 20 seconds. 

Set a large mesh strainer over the mixing bowl and add the flour, baking soda, spices and salt. Sift the mixture down into the batter and give it a stir with your spatula (stirring the flour in a bit will prevent it from flying out of the bowl when you start the mixer.)

Place the mixer on the lowest setting and beat just until the flour is completely blended.

Use a cookie scoop or a tablespoon and shape the dough in your hands forming 1-1/2 inch balls. 

Add the course sugar to a shallow dish. Roll the balls in the sugar and place them on the parchment-lined baking sheet. Leave space between each cookie.   

Bake the cookies in the preheated oven until they are browned, puffed up and the edges have begun to set while the centers are soft—about 11 minutes. 

The cookies will have those beautiful cracks and appear to be undercooked.  Do not over bake, they will continue baking from residual heat once removed from the oven.

Remove the baking sheet from the oven and leave the cookies on the baking sheet for 5 minutes, then transfer the cookies to a wire rack to finish cooling.