Cut the pumpkin flesh into pieces and cook in a pan with salt and water for about 20 minutes. Once soft, take off the heat, strain and crush with a fork.
Mix the pumpkin pulp with the sugar in a bowl. Add the melted butter, eggs and hazelnut drink and stir well.
Use another bowl to mix the flour, baking powder and cinnamon together. When you have a smooth paste, add to the other bowl and mix all the ingredients together gently.
Grease a mould with extra-virgin olive oil, pour in the mixture and bake at 180 ºC for about 25 minutes (depending on the thickness of the pie and the kind of mould you use).
You can use some walnuts as topping to make it extra delicious!