Preheat oven to 325 degrees. Spray 16 half pint jars or 8 pint jars with cooking spray.
In a large bowl, cream sugar and butter together.
Add pumpkin, eggs, and applesauce. Mix to combine
In a separate bowl, whisk dry ingredients together.
Add the dry ingredients to the wet, stir until combined.
Add pecans and stir.
Divide the batter equally among the mason jars.
Place the mason jars on a baking sheet and bake for 45-55 minutes.
Let the jars thoroughly cool before handling.
Top with butter before serving.