Directions

• For the caramel: Generously butter two 10x15 jelly roll pans. Larger pans will work, too, but smaller ones won't. Place the pans on cooling racks.
• In a large saucepan over medium heat combine the corn syrup, 1 cup of the heavy cream, sugar, and pinch of salt. Stir well.
• Set pan over heat and stir constantly until the mixture comes to a bubble. This will take about 10 to 12 minutes. The mixture will appear milky at first, then lose some of its opaqueness as it heats.
• Once the mixture boils, very slowly add the remaining heavy cream, stirring constantly. Be careful not to disrupt the boil. Lower the heat to medium-low. Set a timer for 6 minutes and allow the mixture to bubble. It will rise high and bubble quite a bit during this 6-minute stage.
• When the time is up, add the butter, 2 to 3 cubes at a time, and mix until butter has melted.
• Insert your candy thermometer and let the mixture bubble until it reaches 250 degrees. When you first insert the thermometer, the temperature will be around 200 to 217 degrees. It will take a good 30 to 40 minutes for the mixture to reach 250. Do not rush this phase by turning up the heat. This is when the caramel takes on its amber color.
• When the thermometer reads 250, remove the pan from the heat and pour half of the caramel in one pan and half in the other. Allow the caramel to cool. While you're waiting, make the cream filling.
• For the cream filling: In the bowl of a stand mixer fitted with the paddle attachment, cream together sugar, shortening, and vanilla. The mixture will be dry and crumbly and you'll probably wonder if you've done something wrong. Don't worry -- you're on the right track. Stop the mixer and scrape down the edges several times.
• Place 1/4 cup water in a small bowl and sprinkle the gelatin over. Let stand until absorbed.
• Microwave gelatin for 10 seconds or until clear and liquid. Add to the bowl of the running mixer.
• The mixture will soften and become thick and doughy. Mix the heck out of it until it starts climbing the sides of the bowl. Scrape down the sides (and bottom, especially if using a KitchenAid) and mix again.
• Place a portion of the dough in a disposable pastry bag or zip-top bag with the corner snipped. Make sure the hole is big enough to pipe a nice thick line of cream filling -- at least 1/4 inch. Cover the bowl of cream filling with a damp towel so it doesn't dry out.
• Assemble: Lay out several sheets of parchment or wax paper on a work surface, preferably a large cutting board or a surface you don't mind cutting on.
• Remove the caramel from one of the pans. It should remove easily if you lift one corner and peel the entire slab of caramel away from the buttered pan. Place it on the paper-covered work surface.
• Cover caramel with additional wax paper and roll it a little thinner with a rolling pin. Try to achieve an even thickness.
• Remove paper and cut caramel into long strips, about 2 to 2 1/2 inches wide. Pipe a line of cream filling down one side of the length of the caramel.
• Roll cream filling into the caramel. The caramel will fold over easily and overlap. Roll and gently stretch into a 16-inch length. Cut into two 8-inch pieces. Tip: the caramel rope will squeeze together when you cut it, making the ends flat. You can either squeeze it back the other way to make a round end, or refrigerate the candy for a few minutes before cutting. Once chilled, the ends will snap off evenly when cut with a sharp knife.
• Repeat with remaining caramel and cream. This will take some time, as there is a lot of candy to work with.
• Roll the candy in powdered sugar and dust off any excess. Wrap each candy in a layer of plastic wrap, then in a length of wax paper with the ends twisted. This helps the candy keep its shape.