This has been one of my go-to basic brownie recipes for years. I got it from the red Betty Crocker cookbook back when I was a teenager. This is a nice recipe to build from -- stir in ½-1 cup of chocolate chips, nuts, or chopped candies, or add a few tablespoons of rum or other liqueur. You can even swirl in some peanut butter or chocolate syrup before baking. Yum!!
1 C sugar
½ C butter, softened
1 tsp vanilla
2 eggs
2/3 C flour
½ C cocoa
½ tsp baking powder
½ tsp salt
Preheat oven to 350°F. Mix sugar, butter, vanilla, and eggs. Stir in remaining ingredients. Spread in greased 8" square pan. Bake until toothpick inserted in center comes out clean (don't overbake), 25 to 30 minutes. Cool and cut in squares.