Preheat oven to 350° F. Line a baking sheet with parchment paper or a silpat mat. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat room temperature butter, egg, sugar and vanilla until well combined (about 1 minute)
In a separate bowl, combine flour and salt. Slowly add flour mixture to butter mixture and mix until just combined. Dough will be stiff. Add mini chocolate chips and mix just until evenly distributed.
Shape dough with your hands into 2 inch "logs" and place 2 inches apart on prepared baking sheet.
Bake on center rack for 8-10 minutes until just set, not brown.
Allow cookies to cool on cookie sheet for about 3 minutes, then transfer to cooling rack.
While cookies are cooling, put chocolate chips in a microwave safe bowl and heat for 30 seconds at a time, stirring after each time. Careful not to burn your chocolate.
Place toffee chips in a small bowl.
Once cookies are cool, dip one half of the cookie into the chocolate and shake or gently scrape off the excess. Gently roll the same half of each cookie in toffee chips. Place back on cooling rack to set.