Grandma's Chocolate Zucchini Brownies

Step 1
Preheat an oven to 350 degrees F (175 degrees C). Grease a jelly roll pan.

Step 2
Sift flour, cocoa powder, baking soda, and salt together in a bowl.

Step 3
Beat the butter and 1 1/2 cups sugar with an electric mixer in a large bowl until smooth. Beat the first egg into the butter until completely blended, then beat in the vanilla extract with the last egg. Mix in the flour mixture until just incorporated. Fold in the zucchini; mixing just enough to evenly combine. Pour mixture into prepared pan. Sprinkle the remaining 2 tablespoons sugar, chocolate chips, and walnuts on top.

Step 4
Bake in the preheated oven until the top is dry and the edges have started to pull away from the sides of the pan, 25 to 30 minutes.