Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.

In a bowl, mix rolled oats, flour, ground ginger, cinnamon, and baking soda.

In another bowl, cream softened butter with granulated and brown sugars until fluffy.

Gradually add dry ingredients to the creamed mixture until combined.

Drop tablespoon-sized dough onto prepared sheets, spaced two inches apart. Bake for 10-12 minutes until golden around edges.

For the filling, mix powdered sugar and vanilla extract with softened butter until smooth.

Once cookies are cooled, spread filling between two cookies to create pies.