Preheat oven to 180C/356F. Line two baking sheets with parchment paper or a silicone baking mat.
Using a hand mixer, beat butter and sugars together. Mix on low until just creamy.
Add flax egg and vanilla, and beat on low until just combined
In another bowl sieve together flours, baking powder, baking soda, and salt and whisk together until combined. Add to large bowl and mix on low until just combined. You can also mix together with a large spoon or your hands.
Pour in the chocolate chips and use your hands to fold in the chocolate chips
Using a large spoon, weigh out 90g of dough, roll into a perfect ball.
Put bread crumbs into a small bowl and cover dough ball in bread crumbs. Place on baking tray. Repeat the process and put 4 balls per tray.
Bake in the oven at 180C/356F for 15 - 18 minutes or until tops are golden brown and slightly firm to touch
Let cool on tray for about 12 minutes before serving warm, or transfer to a wire rack to cool down
Sprinkle sea salt over the top of cookies