Preheat oven to 350 F, and lightly grease a 9 inch cake pan.
Place 2 tbsps butter or coconut oil into cake pan, and put pan into preheating oven for a couple minutes to melt butter or oil. Once melted, make sure butter or oil is evenly distributed all over the bottom of the pan.
Sprinkle 2 tbsps coconut sugar or granulated low carb sweetener all over the melted butter or oil.
Place blackberries on top of butter- sweetener layer, as seen in photo above. Set aside.
In a large mixing bowl combine all the “bread pudding cake layer” ingredients except for the coconut flour and chopped blackberries. Mix thoroughly, then add the coconut flour and mix well, scraping sides of bowl, and braking up any coconut flour clumps. Add the chopped blackberries and gently mix in.
Spoon cake batter on top of fruit layer in pan. Spread cake batter evenly across entire pan.
Bake for 30 minutes or until top of cake is browned and center is set.
Remove from oven and let cool completely.
Use a butter knife between cake and edge of pan and slide around to loosen cake from pan. Turn cake pan upside down onto a large plate or serving platter. Cake should fall onto plate, but if not, then use a turning spatula to lift gently under cake a little, and then turn upside down onto plate.
Slice and serve.
Should be stored in fridge, if serving later.