Add sugar, corn syrup, heavy cream, butter, semisweet chocolate chips in a medium nonstick saucepan over medium heat.
Stir the mixture constantly with a wooden spoon until the candy thermometer reads 240 degrees F. Remove from heat immediately.
Stir in vanilla extract.
Pour in a rectangular 9x13 pan, that's been lined with parchment paper. Make sure two sides of the paper are extending over the long edges of the pan. Spread butter or oil generously on the paper.
Let it cool to room temperature and then cover with foil and refrigerate until firm (usually overnight).
Remove pan from fridge and then, invert the slab of caramel on a wooden cutting board that's lined with wax paper.
Peel off the parchment paper and discard.
If it's too hard to cut, let it sit for about 15 minutes at room temperature or until it softens slightly.
Spray a long, sharp non-serrated knife with oil and make slices and cut out small 1 inch suare pieces. Be sure to wipe the knife clean between each cut and spray it with oil.
Dip each caramel square in melted chocolate.
Place it on a tray, lined with wax paper and sprinkle some flaky sea salt.
Once the chocolate sets, remove from wax paper and wrap each candy in a wrapper or place them in mini candy cups. Enjoy!