Sanni, You're very welcome, I'm glad I could help.
To score the brownies, just cut them very lightly, so that you only break the top "crust." You do this when they are warm because then they cut more neatly. If you wait to cut them until they are completely cooled, the tops tend to shatter and crack, and they look a mess.

Here's the Butterscotch recipe from the same edition of Joy of Cooking:

Butterscotch Brownies - about 16 thin squares
Comment: An all-time favorite, easily made.

Preheat oven to 350 degrees.
Melt in a saucepan:
1/4 cup butter
Stir into it until dissolved:
1 cup brown sugar
Cool these ingredients slightly. Beat in well:
1 egg
1 teaspoon vanilla
Sift, then measure:
1/2 cup all-purpose flour
Resift it with:
1 teaspoon double-acting baking powder
1/2 teaspoon salt
Stir these ingredients into the butter mixture.
Add:
1/2 to 1 cup finely chopped nuts or 3/4 cup grated coconut
Chopped dates or figs may be substituted entirely or in part. Use a little of the flour over them. Pour the batter into a greased 9x9-inch pan. Bake for about 20 to 25 minutes. Cut into bars when cool.