1. Preheat the oven to 200C. Peel the pumpkin and cut into cubes. Steam for 10 min or until soft. Leave to cool, and when cool enough to handle puree the flesh in a blender. You should have about 350g puree (give or take). Set aside.
2. In a large bowl, mix the polenta, flour. baking powder, salt, baking soda and nutmeg to combine. Set aside.
3. In a separate bowl, mix the buttermilk, pumpkin puree and egg together. Set aside
4. Put the butter in a 20cm square cake pan and pop it into the oven to melt. Once melted, swirl the butter around the base and sides of the pan then add tip the excess butter into the buttermilk mixture and whisk it together
5. Add the pumpkin mixture to the polenta mixture and mix until just combined. Pour the batter into the prepared pan and scatter the pumpkin seeds over the top.
6. Bake for 25 minutes or until lightly golden and the centre springs back when gently pressed. Leave to cool for 10 minutes in the pan before turning out onto a wire rack. Best served warm.