Preheat the oven to 375 degrees F.
Butter and flour a 9 by 13inch glass baking dish.
Put the sugar in a large bowl.
Melt the butter in a small skillet or in the microwave in a glass measuring cup.
Stir the butter into the sugar until smooth, cool to room temperature.
Meanwhile, in another medium bowl, whisk the flour, baking soda, and salt together.
Beat the eggs and vanilla into the sugar mixture.
Add the flour mixture a bit at a time and mix until a smooth thick batter forms.
Fold in the chips, as desired.
Spoon the batter to the prepared dish and spread to evenly fill the dish.
Bake until the blondies are light brown around the edges and a toothpick inserted in the center comes out clean, about 20 to 25 minutes.
Remove from the oven and let cool slightly. Invert onto a rack and cool completely.
Cut into squares and serve.