1. Preheat the oven to 350 degrees Fahrenheit and grease an eight-inch pan.
2. Melt the butter and allow it to cool slightly.
3. Mix the sugar and then the butter.
4. Add the eggs and the vanilla and blend until incorporated.
5. Add in the dry ingredients all at once and mix until smooth.
6. Add in the chocolate chips (if desired) and mix briefly.
7. Pour the batter into the pan and place in the center of the oven. Bake 25 to 30 minutes, until a toothpick in the center comes out clean or with baked crumbs.
8. Cool on a rack and then slice into desired-size squares.