4 sticks (1 lb) butter (salted or unsalted)
1 teaspoon kosher salt
2 rounded cups white sugar
1 cup semi-sweet chocolate chips
4 Tablespoons water
2 cups sliced almonds
1/2 cup chopped almonds
Grease a rimmed 12″x17″ or 13″x18″ jelly roll or sheet pan (I used nonstick cooking spray).
Combine butter, sugar, salt, and water in a large saucepan or pot over medium heat.
Bring to a boil, stirring gently but constantly. It will gradually change color and consistency, from thin to thick, light yellow to darker golden brown.
Cook till it reaches a smooth, dark brown color, or till a candy thermometer reaches 298 degrees. This will probably take about 20 minutes.
Remove from heat and add sliced almonds, stirring to combine.
Pour onto baking sheet, spreading evenly with a silicon spatula or offset spatula.
Immediately sprinkle chocolate chips evenly over the top of the toffee, and let sit for a few minutes to soften.
Use a spatula to spread the chocolate evenly over the toffee.
Sprinkle with chopped almonds.
Once completely cooled, turn onto a large cutting board and use a knife to break it into pieces.
Store in an airtight container.