Preheat oven to 350 degrees Fahrenheit. Line a baking sheet with Gefen Parchment Paper.

In the bowl of an electric mixer, beat margarine and sugar until fluffy.

Mix in egg and vanilla.

In a separate bowl, combine flour, oats, baking soda, and salt.

Add dry ingredients to the wet mixture and mix until just combined.

Use a tablespoon to measure scoops. Roll and slightly flatten balls and place on baking sheet with some room to spread.

Bake for 10 minutes or until edges of the cookies are set and the centers have puffed up but are still underdone.

Allow cookies to cool completely.

While cookies cool, combine all cream ingredients in a mixer fit with the whisk attachment. Beat on low, gradually increasing to high until mixture is light and fluffy.

Transfer to a piping bag fit with a round tip.

Pipe cream filling onto the back of one of the cookies and sandwich together with another cookie. Repeat for remaining cookies.