For the cookies: Preheat oven to 350 degrees.
Mix together dry ingredients in a medium bowl and set aside.
In a large bowl or stand mixer, beat together the butter and brown sugar until combined.
Stir in egg, molasses and chai.
Add dry ingredients and mix until dough is combined. Should be somewhere between dough and batter consistency.
Drop round spoonfuls onto cookie sheet and space about 2 inches apart. Bake for 10 minutes. Let cookies cool on rack while you make the filling.
For the filling: Blend butter and cream cheese together in bowl or stand mixer. Stir in vanilla.
Add powdered sugar and blend until smooth and creamy. Stir in spiced chai mix until fully combined.
Assemble the pies: Spread frosting on bottom of one cookie and top with another to form whoopie pie.
Store in an airtight container in the refrigerator.