Preheat oven to 350 F.
Using a stand mixer, add room temperature vegan butter and coconut sugar. If you don't have a stand mixer, you can mix everything together by hand in a large bowl
Mix on a low speed for about 1 minute until incorporated.
Next, add eggs, molasses, and vanilla extract, mixing for about 30 seconds more.
Add flour, baking powder, cinnamon, nutmeg, sea salt, mixing for about 30 second more.
Finally, add the rolled oats. The dough should be pretty sticky.
Line a baking sheet with parchment paper.
Using a cookie scoop, form 12 cookies and spread them out, about 2 inches apart. If your baking sheet is small to accommodate all of the cookies, use two baking sheets or just bake them in two separate batches.
Gently flatten each cookie to about 3/4 inch thick. Bake for 12-13 minutes.
Remove from oven and let cool completely. This is VERY important!
Once the cookies have cooled cooled, make the frosting
In a stand mixer, beat the softened vegan butter.
Next, fold in the powdered sugar, almond milk, vanilla, and salt. The frosting will be THICK, and that’s a good thing! If it’s too thick, you can add a touch more milk. But be gentle on the milk, you don’t want runny frosting!
Once the cookies are cooled, spread your frosting on one cookie and use a second one to sandwich them together. Eat, and enjoy!