preheat oven to 325*.whisk first 8 ingredients in medium bowl, using electric mixer, beat butter, sugar, molasses and vanilla in a large bowl -- to blend -- add eggs one at a time, beating till well blended after each addition -- beat in pumpkin. Beat in dry ingredients in 3 additions, alternately with buttermilk in 2 additiona, beating just until combined.
Line 2 rimmed baking sheets with parchment paper -- drop dough by rounded tablespoons onto prepared pans about 2" apart.
bake cookie sheets one at a time until toothpick inserted near the center comes out clean -- about 13 minutes.cool cookies on sheets -- repeat with remaining dough --
spread 2 tbls filling on flat side of cookie.top with second cookie, forming sandwich -- .