In a large bowl, stir together the granulated and brown sugars, melted butter, and salt.
Stir in the eggs until completely incorporated. Add the vanilla and stir to combine.
Add the flour and baking soda and stir until there are no lumps or white streaks.
Remove the Heath bars from the freezer and smack on the counter to break into pieces. Add to the cookie dough and fold to incorporate.
Cover the bowl with plastic wrap and chill in the refrigerator for at least 1 hour (or freeze for up to 3 months).
Preheat the oven to 350°F (180°C). Line 2 baking sheets with parchment paper.
Scoop the chilled cookie dough onto the prepared baking sheets, spacing about 2 inches apart. Bake for 11–13 minutes, or until the edges just start to brown. Let the cookies cool on the baking sheets for about 10 minutes.