Preheat the oven to 300° and grease and flour a 13x9 baking dish. Set aside.
In a large bowl, beat shortening, sugar, eggs, vanilla and pumpkin puree together until creamy.
In a medium bowl, whisk flour, baking powder, baking soda, cloves, cinnamon, nutmeg and salt together.
Mix dry ingredients into wet ingredients until combined. Stir in chopped pecans and spoon cake batter into the prepared baking dish (batter will be thick).
Bake for approximately 60-70 minutes or until a wooden toothpick inserted in the center comes out clean.
Let cool completely.