This is, hands down, the best (and easiest) basic brownie recipe out there. I think it came out of my mom's red Betty Crocker cookbook, which was likely a wedding present when my parents got married back in the Dark Ages. At any rate, the recipe is incredibly easy and always comes out well (as long as the oven is up to temperature, which I had problems with once and ended up with raw brownies. Brownie batter is yummy, but not what you're expecting cooked brownies and serving them to a husband's co-worker/friend).
1 cup sugar
¼ cup cocoa powder
4 tbsp shortening
4 tbsp butter
¾ cup flour
¾ cup nuts (optional)
2 tsp. vanilla
1/8 tsp baking powder
1. Melt shortening and butter, then add sugar.
2. Add all other ingredients, adding eggs on and a time and incorporating before adding the next one. Mix until combined.
3. Bake at 350 degrees for 30 minutes in greased glass dish.
Lessons learned: A few drops of almond extract and mint chocolate chips are really good in this recipe. So are chocolate chips. And I bet toffee bits would be tasty, too. The only thing that didn't work well in this recipe are marshmallows.
I usually double the recipe and up the cooking time by almost 20 minutes. They still stay soft and delicious. If I double the recipe, I use a Pyrex casserole dish. A single batch will fit comfortable in an 8x8 pan.