1.Preheat the oven to 375 degree.

2. Melt 1 cup of butter and allow it to cool for 5 minutes.

3. In a large mixing bowl, add melted butter, brown sugar and white sugar. Add in the eggs and vanilla extract.

4. Add in flour, baking soda and cinnamon. Stir until combined. Add oats and mix until combined. Dig down to the bottom of the bowl to make sure you incorporate the flour into the wet ingredients. 

5. Line a baking sheet with parchment paper. Using a 3 tablespoon cookie scoop, or a large spoon, drop the dough onto the lined baking sheet  3” apart. 

6. Bake for 10-13 minutes, until the edges are golden brown. Let pan sit on a wire rack for about 10 minutes to cool.  Then, slide off so the cookies cool right on the rack. Using the same cookie sheet with new parchment paper, finish what's left of the batter and make the remaining cookies.

7.When the cookies are completely cool you can spread filling on one cookie and sandwich another on top.

To make the filling:

1.Using a stand mixer or hand held mixer, cream the butter  for 1 minute, until fluffy

2.Add powdered sugar, mix for 2 minutes. You may need to stop and scrape down the sides.

3.Add half+half and vanilla. Beat for another 2 minutes or more until fluffy and well combined.

Enjoy these yummy whoopie pies!