Heat oven to 350. Line an 8x8 baking pan with foil and spray with nonstick cooking spray. Set aside.
In a large bowl, melt the butter using the microwave. I always start with 60 seconds at 50% power and then stir to melt completely. Add sugar and egg and vanilla and mix well. Add flour, baking powder, baking soda and mix. Fold in chocolate chips.
Spread batter into pan and sprinkle with sea salt.
Bake 20-25 minutes until browned and toothpick inserted in the center comes out clean. Cool completely.
Remove bars from pan. Remove foil from bars and cut. Makes about 16-20 bars.