SUGARED ALMONDS: Preheat the oven to 350 degrees F and place a rack in the center of the oven. In a large bowl, combine the brown sugar and 1 teaspoon of salt. Mix in 1 tablespoon water and stir until you get a glaze. Add in the almonds and toss until evenly coated. Spread almonds out evenly on a parchment paper-lined baking sheet and toast for 8 to 10 minutes, or until shiny and light golden. Remove almonds from the oven and let cool completely. Transfer almonds to a cutting board and give them a rough/coarse chop. Set aside for later. Here's a good time to also chop and measure your chocolate.
TOFFEE PREP: Line a rimmed half sheet pan (13x18 inches) with a Silpat baking mat or generously butter the pan. I highly recommend the Silpat baking mat for ease of removal and cleaning.
LOW HEAT: Heat a large, 2-quart ceramic pan over low heat for 30 seconds. Take one of the sticks of butter and rub it over the bottom and the sides of the pan. Then add that stick of butter to the pot along with the remaining butter. Carefully add the sugar to the very center of the pan and pour the water carefully right on top of the sugar. Add the salt. We want to avoid any sugar crystals getting on the sides of the pan. Keeping the mixture over low heat, use a wooden spoon to stir slowly and gently to melt the butter and dissolve the sugar. Be patient during this process; it should take 10-12 minutes to completely dissolve the sugar. (Low and slow is the key here.) Use a wet pastry brush to brush any sugar off the sides of the pan. A light-colored pan helps you to see if any sugar is clinging to the sides. Near the end of the 10-12 minutes the mixture will likely start boiling up a little bit.
MED HEAT: Increase the heat to a little over medium (but not quite medium high). Add the candy thermometer to the pan and make sure it's not touching the bottom. From here on out, stir constantly at a low and even speed and in the same direction. The mixture will come to a boil and slowly start to take on color. This takes about 8-10 minutes. Cook the toffee to hard-crack stage (300 degrees F at sea level) (Note: In high-altitude areas, such as Utah where I live, cook to 285-290). Watch it very carefully as the heat is rising at the end, because it may reach the temperature quickly. The minute it reaches hard-crack stage, pour it out from the pot onto the prepared sheet pan. Working quickly, tilt the sheet pan from side to side, and up and down, to get the candy in one even layer and to fill most of the pan. It's okay if it goes up the sides a little.
TOP TOFFEE: Let toffee sit at room temperature until it is firm to the touch but still hot, 5 to 8 minutes. Sprinkle the chopped chocolate evenly on the toffee.The chocolate melts quickly; let it melt for a few minutes and then use an offset spatula to evenly spread the chocolate over the toffee. Quickly add in the chopped and sugared almonds. Gently press them in and then let the toffee stand at room temperature until completely firm, about 6-8 hours. When the toffee is completely firm, use your hands to break it into bite-sized pieces.
STORAGE: The toffee can be stored in an airtight container at room temperature for up to 2 weeks.