Beat shortening, brown sugar, pumpkin puree, and white sugar together in a bowl until creamy; add eggs and vanilla extract and beat until smooth.
Whisk flour, baking soda, and cinnamon together in a bowl. Gradually stir flour mixture into pumpkin mixture until dough is well-mixed; slowly stir in oats. Stir butterscotch chips into dough until evenly distributed. Drop dough by the spoonful 2 inches apart onto a baking sheet.
Bake in the preheated oven until light golden brown, 8 to 10 minutes.
