Grease and line a 23 x 33 cm deep tin. Set aside. Add the dry ingredients (buckwheat, shredded coconut, chia seeds, sesame seeds, hemp hearts, cacao/cocoa and coconut flour) into a large mixing bowl and mix well. Set aside.
Add maple syrup, pitted dates, tahini, vanilla and melted coconut oil into a blender, and blend until an even paste forms. Pour this mixture into the dry mix bowl and mix very well. Once everything looks uniform, transfer to the lined tray. Spread evenly then press down firmly to create the bars (you can use the back of a spoon or a flat glass as a mini rolling pin if you wish).
Finally, create the chocolate topping. Use between 200-300g chocolate (more if you want a thicker topping). Bang each bar of chocolate on the bench before opening to break it into small pieces then add to a heatproof bowl with the 1 tsp coconut oil,and set over a baine marie with simmering water (ensure the bowl doesn’t touch the water).
Melt slowly, then once liquid pour over the base, smooth out with a dry spoon and set in the fridge for 4+ hours.
To cut the bars, it is recommended to use a hot, very sharp knife.
Store in an air-tight container in the fridge (up to 2 weeks) or freezer (up to 4 weeks).