Fannie Farmer Brownies

Fannie Farmer was one of the first “scientific” cooks. Her landmark cookbook used precise measurements. When I make this recipe, she probably turns in her grave. I often stray from the strict measures and add various options and surprises. No matter what I do, they always turn out delicious.
Fannie Farmer Brownies
3 oz unsweetened chocolate (or 9 Tblsp cocoa + 3 Tblsp butter)
6 Tblsp butter
1.5 cups sugar
3 eggs
1/4 t salt
3/4 cup flour
1.5 t vanilla
(optional: 3/4 cup walnuts, chocolate chips, dried fruits or 1 t flavored liquor)
Preheat the oven to 350F. Butter a 9″ square pan. Melt the butter and chocolate in a double boiler, stirring until smooth. Stir in the remaining ingredients. Spread in the pan and bake 40 minutes, until dry on top and almost firm to the touch. Cool 15 minutes and cut.
For chewier brownies, double the recipe and bake in a 9×13″ pan