Preheat the oven to 350 °F and line 2-3 large baking sheet with silicone mats.
Cream together butter and sugars in a large bowl. Add the egg, vanilla and molasses and mix until well combined. Add the spices, baking soda and salt and combine. Finally, mix in the oat flour until fully incorporated.
Scoop 1.5 tablespoon of dough and roll into balls. Measure out your rolling sugar into a shallow bowl and roll each dough ball in the sugar. Place spaced out on your prepared baking mat.
Bake for 9-11 minutes until the edges are set.
Allow to cool on the baking sheet for 5 minutes and then move to a wire rack to cool completely.