In a small, microwavable bowl, combine 1 1/2 cups chocolate chips and butter. Microwave in 30 second intervals, stirring in between, until smooth.
In a small bowl, combine flour, baking powder and salt.
In a separate large bowl, whisk together sugar and eggs, then slowly add the warm chocolate mixture until combined. Add in vanilla extract, then stir in flour mixture.
Cool for a few minutes (so the extra chocolate chips won't melt), then stir in 1/2 cup remaining chocolate chips and toffee bits.
Chill in the refrigerator for 15-20 minutes.
Pre-heat oven to 350 degrees. Scoop rounded tablespoons of batter onto cookie sheet.
Bake 8-10 minutes until the outside looks slightly cracked. DON'T OVERCOOK - cookies will be soft and chewy in the center.