Preheat the oven to 375 F, line 2 baking sheets with parchment paper and set aside.
Cream the butter and sugar in the bowl of a stand mixer or in a mixing bowl using a hand mixer on medium speed until light and fluffy, 1-2 minutes.
Add the egg and vanilla extract
Stir together the flour, salt, baking soda, and baking powder in another bowl, then add to the butter and sugar mixture.
Stir in the oats and raisins.
Use a 1 tbsp sized cookie scoop (small size) to scoop the cookies onto your baking sheet. Press slightly to flatten.
Bake 6-8 minutes until the cookies have a very light golden coloring along the bottom edge, rotating the pans once during baking. Remove from the oven and allow to set on the pan for 2-3 minutes before removing to a wire rack to cool completely while you prepare the filling.
Prepare the filling by beating together the coconut oil and butter until combined, then stirring in the powdered sugar and cinnamon. Place into a piping bag with the tip cut off and pipe onto one cookie, then top with another to make your sandwich.
Store in an airtight container up to a week.