Preheat oven to 350 degrees F (180 degrees C). Lightly grease 2 cookie sheets.

Cream the butter until lighter in color and fluffy. Add the 1 1/4 cups sugar and cream together. Beat in egg yolks and vanilla.

Add flour, baking soda, and cream of tartar. Stir until completely combined.

Mix together the 2 tbsp sugar, cinnamon, and pumpkin pie spice in a small, shallow bowl. Roll dough into walnut sized balls and roll in the sugar mixture.

Place on the prepared cookie sheets 2 inches apart. Make a 3/4 inch wide circular indent with your thumb or the back of a small spoon in all the cookies. Bake for 5 minutes in preheated oven.

While the cookies are par-baking, make the pumpkin pie filling. Whisk together all ingredients for pumpkin pie filling until well combined.

Remove cookies from oven. Press indents in if they've risen too much. Fill each indent with pumpkin pie filling, enough to be level with the top of the cookie.

Bake for 8-10 more minutes, until cookies are golden on the bottom and pumpkin pie filling is set. Let cool for at least 5 minutes before serving.