Blondies

I've always preferred blondies over brownies. I guess I'm not as into chocolate as most people. Since I had an early dinner today (around 5pm) and was still hungry, I decided to make some blondies. They are very easy to make and use ingredients that are probably in your pantry already. I tweaked the recipe by America's Test Kitchen by skipping nuts and adding more chocolate chips. The blondies turned out good but not amazing. In my opinion, Zingerman's makes the best blondies and I'm still trying to find a recipe that replicates their magical taste. Do you guys have any ideas?

(Adapted from America's Test Kitchen; makes 36 tiny bars)

Ingredients:
1 1/2 cups flour
1 tsp baking powder
1/2 tsp salt
1 1/2 cup brown sugar, packed
12 tbsp butter, melted and cooled
2 eggs
1 1/2 tsp vanilla
3/4 cup chocolate chips
3/4 cup white chocolate chips

Directions:
- Preheat the oven at 350 degrees F.
- Line a 13 by 9-inch pan with foil and spray with Pam.
- Whisk the flour, baking powder, and salt in a bowl.
- In another bowl, whisk the sugar and butter; add the eggs and vanilla until mixed.
- Fold the dry ingredients into the egg mixture until combined; fold in the chocolate chips.
- Bake for 22 to 25 minutes.