3/4cupchopped bittersweet chocolate (I use 70%)(4 1/2 ounces)
1/4teaspoonflaky sea salt, such as malden
Line a baking sheet with parchment paper for easy cleanup. Spread out half of the chopped almonds into a 10" circle.
Measure the salt and baking soda into a little container, and the vanilla into a separate container, and have them at the ready.
In a medium saucepan, combine the rum, butter and sugars. (Clip a candy thermometer onto the side of the pan if you have one; if using an instant read, just have it handy.) Cook over medium heat, stirring just enough to dissolve the sugar, then continue cooking, gently swirling the pan if the mixture begins to color unevenly, until a thermometer registers 300º.
Immediately remove from the heat and quickly stir in the baking soda, salt and vanilla, mixing just to combine. Pour the mixture onto the circle of nuts, and quickly and gently spread to cover.
Sprinkle the chocolate evenly over the top, let sit for a minute to melt, then spread into an even layer with an offset spatula or butter knife. (Or your finger. That works, too.) Sprinkle the remaining nuts over the top along with the flaky salt.
Let cool at room temperature for 1 - 2 hours to set the chocolate, or, if it's warm, in the fridge. Break or chop into pieces. Store at room temperature for up to two weeks.
Adapted from the illustrious David Lebovitz (who offers some good tips and encouraging words regarding candy making in the previous link).Panela is a cone-shaped sugar available at Latin-American groceries. If you can't find it, you can substitute muscovado or dark brown sugar.Use any nut you like as well; pecans, cashews and brazil nuts would both be lovely.Sugar likes to crystallize, which is what you don't want when making toffee. To minimize the chances of this happening, agitate the sugar mixture as little as possible while it's cooking and when spreading it over the nuts. Have a clean pastry brush and a cup of water handy to brush down the sides of the pot if any crystals start to form. All that being said, fear not: during the countless times I've caramelized sugar, I've only had it crystallize a couple of times. If your mixture does crystallize, you can try adding a few tablespoons of water to the pot, give it a stir (it will bubble vigorously - careful!) and return it to the heat. It may re-dissolve and be saved.Nutritional values are based on one of twelve servings.