Preheat oven to 400 degrees. Grease a 12-capacity muffin tin and set aside.
In a large bowl, sift together the flour, baking powder, baking soda, cinnamon, nutmeg, ginger and salt. Set aside.
In the bowl of a standing mixer, beat the brown sugar and butter at medium speed for 4 minutes, scraping down the sides as needed.
Add the eggs, molasses and buttermilk and continue to mix until well combined.
Reduce speed to low and slowly add the flour mixture until just combined.
Add the canned pumpkin and mix until just combined. Do not over mix.
Scoop the batter into the prepared muffin tins and sprinkle with pepitas. Bake for 15 - 17 minutes until a toothpick inserted into the middle comes out clean. Enjoy warm!