Preheat oven to 350º
Spray 13x9 baking pan
In medium bowl, stir together flour, baking powder and salt. Set aside.
In mixing bowl, combine butter, sugar and brown sugar until smooth.
Add eggs and 2 tsp vanilla, mix.
Add flour mixture until smooth.
Spread in prepared pan, bake 30-35 minutes.
Blondies best if slightly under-cooked. Blondie will sink as cooling.
Using medium sauce pan, heat cream just until hot.
Remove from heat, add chocolate chips. Let sit 1 minute for chips to melt.
Stir until smooth. Add vanilla, stir until mixed.
When cooled, cut blondies, set piece on plate.
Top with sauce and whipped cream (if desired)