I toasted my own almonds, which is pretty easy. I chopped whole natural almonds into small to medium size pieces. You need ¾ cups of chopped almonds. Line a sheet pan with tin foil and spread the chopped almonds around the sheet pan. Toast the almond pieces at 320° F (160° C) for 12 minutes. Oven vary, so monitor them. If they get a light brown, pull them out of the oven. Move them to a plate to cool.
Grease a 9 X 9 baking pan with coconut oil. Unwrap 5 Hershey's chocolate bars and set them aside. In a 2-quart saucepan, clip the candy thermometer to the one side.
Add the butter to the saucepan and melt over a medium heat. Once melted, add the sugar, water, and the light corn syrup and stir to combine. Continue to stir over a medium heat as the mixture thickens. This process takes about 20 minutes for the mixture to reach a temperature of 290° on the candy thermometer. It should be a nice brown color at this point.
Take the pan off the heat and add ½ cup of the toasted almonds to the toffee. Once combined, pour the toffee-almond mixture into the greased pan. Even it out around the pan.
Next, take the candy bars and lay them around the top of the hot toffee. It only takes about a minute for the chocolate bars to soften to the point of spreading it with the back of a spoon. Cover all the toffee. Now take the remaining toasted almonds and sprinkle them on top of the chocolate. Cover the pan with a piece of parchment paper and let it set for at least 6 hours or overnight.
When set, I cut a small square in one corner just to get it started. You can cut rows and squares after the first piece is out.