One quarter of bread recipe calls for 2/3 cup of bread flour. How many cups are needed per recipe?

There are several information's of immense importance already given in the question. based on those given information's the answer to the question can be easily determined.

The number of cups required for making 1/4 of bread recipe = 2/3

Then

Number of cups required to make for making 1 bread recipe = (2/3) / (1/4)

= (2 * 4) / 3

= 8/3 cups

= 2 2/3 cups

So the total number of cups required per recipe is 2 2/3 cups of bread flour. i hope the procedure is clear enough for you to understand.