Cream together the butter and sugars until light and fluffy.
Meanwhile, whisk together the eggs and vanilla in a small bowl.
Sift together the flour, baking soda and salt in a medium bowl.
Alternately add the wet and dry ingredients to the creamed butter, beating until just incorporated.
On a low speed, mix in the chocolate and Mars Bar chunks..
Use a medium cookie scoop to scoop balls of dough onto the prepared trays, allowing room for spreading. Sprinkle each cookie lightly with sea salt (optional, but super delicious).
Refrigerate or freeze the dough for at least an hour.
When you're ready to bake, preheat the oven to 180 C (350 F).
Bake for 12 - 15 minutes, until golden around the edges.
Makes 30 cookies.
Happy baking!
Recipe by Butter Baking at https://www.butterbaking.com/2014/08/25/mars-bar-chocolate-chip-cookies/