Whisk together flour, salt and baking powder in a bowl and keep it ready.
To assemble the jar, layer half of the flour mix in the bottom of the jar.
Add cocoa powder.
Layer the remaining flour mix.
Next add a layer of the brown sugar.
Then a layer of white sugar.
Then add milk chocolate chips.
Then white chocolate chips.
Finally add the nuts.
The jar is ready to be gifted.