Heat the oven to 350°F and line a baking sheet with parchment paper.
In a mixing bowl, beat the softened butter and brown sugar until smooth.
Add the egg and vanilla extract, then stir until combined.
Mix in the rolled oats, flour, baking soda, and cinnamon until a dough forms.
Fold the raisins into the dough.
Scoop rounded tablespoons of dough onto the baking sheet, spacing them a few inches apart.
Bake for 10 to 12 minutes until the edges turn golden.
Remove the sheet from the oven and immediately press two candy eyes into each warm cookie.
Let the cookies cool on the sheet for 5 minutes before moving them to a rack.