Preheat oven to 190 C / Gas 5. Coat a 2lb loaf tin with extra virgin coconut oil.
Place 4 tablespoons coconut oil in a microwave-safe bowl and place in microwave for 30 seconds, or until melted. Set melted coconut oil aside.
In a large bowl, mix the flour, bicarb, ginger, cinnamon, allspice and salt; set aside.
In a large mixing bowl, add the sugar, coconut oil and egg; beat until smooth. Add the butternut squash puree, coconut milk, treacle and vanilla extract. Add dry ingredients in with the wet and mix until smooth.
Tip the cake mixture into the tin and smooth the top. Bake on the middle rack in the centre of the oven until a skewer comes out clean when inserted into the centre of the cake, 45 to 55 minutes. Cool 5 minutes in the tin before turning the cake out onto a rack to cool completely.
To make the butternut puree, you can steam or boil cubed butternut squash. Puree and then cool before using in the recipe.