In a large mixing bowl add the softened butter and light brown sugar. Stir with a spoon until mixed. Read notes above about not creaming together.
Add in the cinnamon, allspice, ginger, salt, molasses, brown rice syrup, egg and vanilla extract. Stir together with a spoon until mixed.
Add in the flour and stir until combined. Can use hands at this point to ensure dough is mixed together.
Divide the dough into three sections. If making all of the cookies then roll out all of the dough between pieces of parchment paper. If saving some dough then wrap in plastic wrap and place in refrigerator. Once the cookie dough is rolled out place in the refrigerator to chill for at least 2 hours.
Preheat the oven to 350°F. Line a large baking sheet with parchment paper or silicone baking mat.
Cut out the cookies and place on the baking sheet. Bake the cookies for about 8-10 minutes. Cookies will still feel soft and edges will be just turning browned.
Allow the cookies to cool on the baking sheet for about 5 minutes. Then remove from the sheet and continue to cool on a wire rack.