Preheat your oven to 375 degrees and line a baking sheet with parchment paper.
In a large bowl and using an electric mixer, combine the eggs, butter, sugar, and vanilla. Beat them until smooth.
Add your flour, salt, and cream of tartar and continue to mix until a soft dough forms.
Roll your dough into 2-inch balls and place them on the cookie sheet. Lightly press your thumb down in the middle of each ball to create a "well" (that will later hold your caramel).
Bake for about 10 minutes or until golden brown. Remove from the oven and allow to cool.
While your cookies are cooling, start on the caramel. Using a microwave safe dish, microwave the caramels and butter using intervals of 20 seconds. Between each 20 seconds, mix thoroughly.
Once melted, stir in the cream/milk and heat again for 20 seconds. Let it stand to cool for about 15 minutes.
Once cooled, spoon the caramel into a pastry bag or Ziploc. Tie it off at the back and snip a corner off the bottom. Pipe your caramel into the center of each cookie.
Sprinkle each cookie with sea salt.
To add a chocolate zig-zag, put some chocolate frosting (straight from the baking shelf is just fine) into a pastry bag and pipe that on as well.
Allow the cookies to set for about 20 minutes before serving.
