Cream together 4 Tbsp butter and ½ cup brown sugar. Add vanilla and egg and mix to combine.
Add flour, baking powder and salt combine until incorporated.
Add toffee chips and stir until well distributed. Reserve several toffee bits for the top, if desired.
Refrigerate the dough for 1 hour or alternatively, freeze for 30 minutes.
Scoop the cookies using roughly 1 Tbsp of dough. Place on a parchment paper lined baking sheet. Bake for 9 minutes at 350°. Centers may not set until cookies have cooled. If you prefer crisp cookies, bake for an additional 1-2 minutes, but keep a close eye on them as they could burn and overcaramelize the toffee bits. Enjoy!