Mix together the ground flaxseed and water in a small dish and leave to set for 10 minutes.
In a large bowl, mix together the tahini, maple syrup and set flaxseed mixture.
Add in the oat flour, cocoa powder and salt. Mix until combined, then transfer into a loaf tin.
Mix the tahini, maple syrup and milk in a small bowl, then drop dollops on top and swirl using a sharp knife. Sprinkle some sesame seeds and a small handful of chopped chocolate on top.
Bake for 20-25 minutes, then leave to cool completely before slicing.
Notes
* I like to use Middle Eastern/Lebanese tahini because it's runny, so it's easier to use in baking. You can find them in your local Asian/ethnic shops or the world food isle in major supermarket. I also sometimes get it from Amazon. ** Make your own by blending oats in a high-speed blender until you have a fine flour. Use gluten-free oats to make the recipe gluten-free.