Preheat oven to 175C.
Grease 12 muffin cups or line with paper muffin liners.
Split pumpkin in half. Remove seeds and strings. Place on baking sheet, cut side down.
Cover with foil and bake in preheated oven until tender, about 90 minutes.
Remove pumpkin pulp and puree in blender. Measure out 2 cups pumpkin puree; set aside.
In a large bowl, stir together flour, sugar, baking soda, baking powder, cloves, cinnamon, nutmeg, allspice and salt.
In a separate bowl, beat together 2 cups pumpkin puree, oil and eggs.
Stir the pumpkin mixture into the flour mixture until smooth.
Scoop batter into prepared muffin cups.
Top each with a single pecan half and pumpkin seeds.
Bake in preheated oven for 20 to 25 minutes, until a toothpick inserted into the center of a muffin comes out clean.