Preheat oven to 350°.
Combine all ingredients for the crust (except butter or coconut oil) in a blender or food processor.
Melt the butter or coconut oil and add it to the mixture.
Lay the crust flat in a prepared 8 x 8 baking tray.
Bake at 350° for about 10 minutes.
In the meantime, prepare the filling: combine eggs, coconut flour, coconut sugar, honey, lemon zest, lemon juice, vanilla extract and salt in a blender. Blend until smooth.
Gently fold in the blackberries to the mixture.
Remove the crust from the oven and allow it to cool before pouring the filling on top.
Sprinkle shredded coconut on top (optional) and place back into the oven at 350° until edges begin to turn golden brown (about 25 mins).
Remove from oven and chill overnight.
Sprinkle on some powdered sugar (optional).
Enjoy! Best served chilled.