Preheat oven to 350 F and line the bottom of 8-inch springform pan with a circle of parchment paper

In a medium bowl, mix cashew butter, coconut flour, maple syrup/agave and coconut milk. Lightly press the dough on the bottom of springform pan and set aside

Place chestnut puree, maple syrup/agave, sea salt and vanilla into a bowl and mix well. Set aside

In a heavy bottom saucepan over low heat melt chocolate and coconut oil. Add to chestnut mix and whisk well. Add the eggs one at a time and whisk until creamy. Using an electric mixer works best

Pour batter in the prepared pan and bake for 35 minutes