Bungie has created a consistent & straight-forward way of earning Bright Dust, by doing the "Orders" on your season hub tab. The Dawning is now like all other "Events" (Solstice, Festival, etc)... they each have their own Event-specific weapons, which you can earn by doing the activity or task associated with said event. For The Dawning, the task is to bake & deliver cookies. You can now earn whatever ingredients you want, no bounty necessary. Once you deliver the cookies, you get a gift in return that either gives you 5 Tier weapons, or Dawning Spirit which can be used to purchase Dawning engrams for 5 Tier weapons.