1) Gathering the data
1/4 cup of brown sugar ------ 1 batch
3/8 ---------------------------------- x
2) Let's solve this problem by setting a proportion to solve this:
1/4 cup of brown sugar ------ 1 batch
3/8 ---------------------------------- x
Since it is a proportion then we can cross multiply those fractions:

3) So with 3/8 cups of sugar, we can make 3/2 batches or 1.5 batches