Preheat the oven to 350 and lightly grease a 9x13 pan.
In a saucepan over low heat, melt the butter, then add the sugar and stir to combine. Heat just until the mixture is hot, but don't let it bubble. Watch for it to start looking shiny as you stir it.
As the butter is heating, n a large bowl beat the 4 eggs until they are fluffy and well blended.
Add in the cocoa, salt, baking powder, and vanilla and mix till smooth.
Add the hot butter & sugar mixture to the egg & cocoa mixture, stirring until smooth.
Add the flour and chocolate chips, again stirring until smooth.
Pour the batter into your prepared pan. Bake for about 30 minutes or until the edges of the brownies look set and a toothpick inserted in the center comes out mostly clean. It's ok if a few crumbs stick to the toothpick...the middle should be very moist, but not unbaked!
Video
Notes
The calories shown are based on the brownies being cut into 20 pieces, with 1 serving being 1 brownie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.