Using a stand or a hand mixer, cream together butter and sugar for 2-3 minutes.

Mix in vanilla, and then add eggs one at a time, mixing between additions. Scrape the sides of the bowl, stir, and then set aside.

In a separate mixing bowl, whisk together the flour, cream of tartar, baking soda, and salt.

Turn the mixer back on and pour the dry ingredients into to the wet ingredients a bit at a time. Mix just until everything is combined.

Fold in the toffee bits.

Cover dough with plastic wrap and chill in the fridge for one hour (or longer, but aim for at least an hour).

Remove dough from fridge & preheat the oven to 350.

Stir together 1/4 c granulated sugar and 3 tsp cinnamon in a shallow bowl. Roll dough into balls, and then roll the dough balls in the cinnamon and sugar mixture and place on the baking pan.

Bake for 9 minutes at 350, remove from oven, and allow to cool for a few minutes on the pan before transferring to a cooling rack.

Repeat with remaining dough & enjoy!