Preheat oven to 190°C (375°F) or 170°C (340°F) for a fan forced oven. Prepare your muffin or cupcake pan.
Steam cook your pumpkin (if not using canned pumkin) and mash or puree then leave to cool.
In a medium-sized bowl, sift your gluten free all purpose flour, cornstarch, spice and baking soda together then add salt and mix well.
In a seperate bowl add your egg and sugars and mix with a whisk or mixer until light, thick and doubled in volume. Slowly drizzle in your oil while mixing slowly and mix until combined.
Add your dry ingredients to the egg and sugar mixture and gently fold through until just combined.
Add your canned or cooled pumpkin and fold through gently again.
Add your cream cheese, sugar, vanilla and egg yolk to a small bowl and whisk together until smooth.
Fill the cupcake cavity about ¾ full and split the cream cheese topping across the 12 muffins (about 1 Tablespoon each) and swirl through using the back of a teaspoon or toothpick.
Bake for 20 minutes or until a toothpick comes out clean or has only a few crumbs attached.
Enjoy!