This is a recipe my sister used to make in Uruguay to introduce people to chocolate American-style. The only thing I added was 1/2 a bag of Reese's baking pieces (think very miniature pb cups). You'll definitely want a glass of milk or a scoop of vanilla ice cream to go with these.
Mix all together in the following order:
1/2 c. melted butter
1 c. sugar
1/4 c. cocoa
1 c. flour
1 tsp. vanilla
1/4 tsp. salt
1/2-1 c. nuts (optional, of course)
Spread in a greased 8x8 pan and bake at 350 for 25-30 minutes. Double this recipe to make a 9x13 pan of brownies. If you choose to add the baking pieces, stir them in just before baking.