Add a little bit of the flour at a time, making sure to blend well; the mixture will get increasingly thick, so it's easiest to add it slowly to make sure that you don't end up with any
unmixed flour pockets.
Fold everything together gently just until combined and
no flour pockets remain.
Add wet mixture to dry and mix well until
all flour pockets are incorporated into the batter.
Stir until everything is well incorporated (
no flour pockets left).
Add the flour mixture in two additions, folding with a rubber spatula until
no flour pockets remain.
Add the dry ingredients and mix briefly on low speed, then finish mixing by hand, stirring just until
no flour pockets remain.
Stir gently and just enough until there are
no flour pockets any more, but no more than that.
Stir in chocolate chips and nuts (if using), giving dough final stir to ensure
no flour pockets remain.
Stop the blender once or twice to scrape down the sides and to make sure there are
no flour pockets.
Add the pumpkin mixture to the dry ingredients, stirring just until combined and
no flour pockets remain.