Using a stand mixer fitted with paddle attachment cream the room temperature butter and sugar until light and fluffy. Mix in the egg yolk and vanilla extract until well combined. Mix the flour and salt into the wet ingredients until just combined.
Transfer about 1 tablespoon (15 ml) of pumpkin pie filling into the par-baked cookies. Bake an additional 10 - 15 minutes or until the edges of the cookie are golden brown and the pumpkin pie filling it set.