Line the bottom and sides of a rectangular 9 by 12-inch brownie pan with parchment paper.
Combine the sugar, corn syrup, 1/2 cup water, kosher salt and cream of tartar in a heavy 4-quart saucepan. Cover and cook over medium-high heat until the mixture is boiling, about 4 minutes.
Remove the lid and attach a candy thermometer. DON'T STIR IT, the caramel will crystallize. When the syrup reaches 300 degrees F, 6 to 7 minutes, you can gently swirl the pan to even out the caramelization. Cook to 350 degrees F and remove from the heat; the caramel will be dark amber.
Add the cream and butter. Stir with a HEATPROOF rubber spatula. Return the caramel to medium heat, stir until the butter is completely melted and continue cooking until it reaches 260 degrees F. Let the caramel cool in the pan for 5 to 10 minutes. Stir in the puffed rice cereal and pour into the prepared brownie pan. Sprinkle the coarse salt on top. Press in with your hands when the caramel is cool. Let the caramel set up for 4 hours, or overnight in a cool dry spot.
Temper your chocolate: Place two-thirds of the chocolate in a microwave-safe bowl. Microwave on medium in 30 second intervals until fully melted, about 3 minutes. The temperature of the chocolate should be around 120 degrees F. Add the remaining one-third of the chocolate and stir until fully incorporated. Keep stirring until the chocolate reaches 85 degrees F. You can test it by holding the chocolate covered spatula to your lower lip. When it no longer feels warm, the chocolate is ready. You can warm it SLIGHTLY, to 90 degrees F, to make it more fluid. This can be done by microwaving it in 2 second intervals. I am not joking - 2 seconds, no more! Keep the chocolate on a heating pad set to low if you are not going to use it for a while. Make sure the temperature stays between 85 and 90 degrees F. If it goes over, you will have to start the process again. And you DON'T want to do that.
Line baking sheets with parchment paper. Remove the caramel from the pan and cut into desired size. Regular, mini or KING SIZE! Dip in the tempered dark chocolate using 2 forks. Tap the forks on the side of the bowl to remove any extra chocolate and insure a THIN coating. Carefully place the bars on the prepared baking sheets and let set in a cool, dry place until the chocolate hardens. Decorate with edible gold and edible glitter!