Place the vegan butter in a microwave safe bowl and microwave, just until fully melted. Alternatively, place the vegan butter in a small pot and, over the lowest flame possible, melt the vegan butter.
In a small bowl, whisk together the flour, ground oatmeal, baking soda, baking powder, salt and cinnamon. Set aside.
In a large bowl, mix together the sugar, light brown sugar and the melted vegan butter. Add in the oat milk and vanilla. Stir until fully combined.
Stir in the dry ingredients, just until the flour is almost fully incorporated. Add the oatmeal, stirring just until combined, and then add the raisins, stirring until they appear evenly distributed.
Cover the dough with plastic wrap and chill in the refrigerator for at least 30 minutes and up to 48 hours.
Preheat oven to 350° F.
Scoop the dough with a small cookie scoop (1½ Tablespoons) or weigh out 30 grams worth of dough per cookie. Spread the cookies approximately 2 inches apart on a parchment lined baking sheet.
Bake for 12-14 minutes, just until the edges barely start to brown. The middle of the cookies may look raw, but they will continue to cook from the residual heat when they come out of the oven. Cool completely on pan.