Preheat oven to 350°F.
Line two baking sheets with parchment paper or Silpats.
In a large bowl, whisk together the flour, salt, baking powder, baking soda, cinnamon, ginger, and cloves and set aside.
In a separate bowl, whisk together the brown sugar and oil until combined. Add the canned pumpkin purée and whisk to combine thoroughly. Add the eggs and vanilla and whisk until combined.
Sprinkle portions of the flour mixture intermittently into the pumpkin mixture, whisking in each part until well combined.
Use an ice cream scoop to drop portions of the batter onto each of the prepared baking sheets, spacing them at least 3 inches apart.
Bake the whoopie pies for 12 to 15 minutes until the cakes are just starting to crack on top and a toothpick inserted into the center comes out clean.
Remove the whoopie pies from the oven and let them cool completely while you make the filling.