Preheat oven to 350 degrees. Line 2 baking sheets with parchment paper.
In a medium size bowl, combine flour, cocoa, salt, baking powder, ginger and cardamom. Mix well. Set aside.
In the bowl of an electric mixer, combine coconut oil and sugar. Beat on medium high speed until smooth. Add in eggs and beat on medium speed an additional 90 seconds. Add in vanilla. Turn mixer to lowest setting, slowly pour in the flour mixture. Only stir the mixture until just combined. Fold the chocolate chips in with a spatula.
Scoop batter into balls the diameter of quarters and place on the prepared cookie sheets, leaving spacing of 2-3 inches between (they will spread a lot).
Bake 8-9 minutes. Remove from oven and cool on sheets for 3 minutes. Remove to wire rack to cool completely.
While the cookies are cooling, prepare the "buttercream"
For the buttercream
Combine sugar, coconut oil and shortening in a stand mixer. Beat on medium high speed until ingredients are incorporated. Add milk 1 tablespoon at a time until the frosting is the desired consistency. Beat on high for 2 minutes until light and fluffy.
Scoop and equal amount of frosting onto half of the cookies and top with a second cookie, making a sandwich. Press lightly to spread the frosting evenly between the two cookies.
If your frosting gets too soft, refrigerate the cookies in an airtight container.