Mix the oats, flour, baking soda, and spices together. Set aside.
In your mixer (if you don't have a mixer you can use a spoon and a bowl), add the butter and both sugars (brown and regular). Mix this together until soft. Follow this up with vanilla extract and eggs. Last, add the molasses. Make sure you scrape down your mixer as this is mixing together.
Add the flour mix to the wet mixture. Make sure you scrape down while everything is mixing.
Cover the dough in a bowl and chill for 30 minutes. Heat your oven to 350 and cook for 12 minutes. While the cookies are in the oven make the icing.
When the cookies are done, leave them on the baking sheet for a few minutes and move them to a wire rack. Dip in the icing once they cool down. The icing takes a while to harden so place some paper towels down underneath your wire rack when you start the icing process.