Sift the dry ingredients in a bowl and whisk to blend.
Cream butter and sugar together until light and fluffy, about 3 minutes.
Beat in egg and molasses and mix until smooth.
Gradually add the dry ingredients, while mixing on low, and mix until the dough comes together.
Turn out onto a floured surface and knead the dough a couple of times until it becomes smooth. Divide in two and form into disks.
Wrap in plastic and chill for at least 3 hours, or overnight.
Preheat oven to 350°F.
Place a piece of parchment paper onto your counter
Roll the dough out on to about 1/4 inch thickness.
Cut out your cookies and place on a parchment or silpat lined baking sheet.
Bake for 10 minutes, (rotating the tray halfway through if your oven cooks unevenly).
Let the cookies cool on the baking sheet for a few minutes before moving them to a cooling rack.