The best Blondies!

So I never made Blondies before but always wondered about them.
I had guests over this weekend and decided to try bakingblonde's recipe
she had on her blog. I (and my guests) immediately fell in love with these
amazing treats. I added semi-sweet chocolate chips and pecans but I am
seeing the possibilities are endless.

Basic Blondies
6-7 TBS butter, melted
1 cup brown sugar
1 egg
1 tsp. vanilla extract
1/4 tsp salt
1 cup flour
1/4 tsp baking powder (optional, creates lighter blondie texture)

Preheat oven to 350.Line an 8x8 pan with foil and lightly spray with PAM.
In a large microwave safe mixing bowl melt the butter. Allow to cool for 5 mintues.
Mix the brown sugar with the melted butter and beat until smooth.
Beat in egg and then vanilla. Add salt, stir in flour and baking powder (if using).
Mix in any additions (some ideas below).
Pour into prepared pan and use a greased spatula to evenly spread
mixture in pan and level the top. Bake for 20-25 minutes or until set in the middle.
Cool before cutting.