You will want to get a good heavy frying pan for this recipe. Make it big, because the mixture does boil.
Also, you will need to use your senses when cooking this one. You will be watching for smoke. That tells you that you are starting to burn the sugars just enough to crystallize them. You will also want to follow your sense of smell. It will start to smell really yummy just before you get to the right stages. It will also turn a nice toffee color when it is just about ready. So watch for that.
Shown below are different variations. Some with Almond slivers, some that are plain and some with chocolate. I think the almond slivers with out chocolate are my favorite! To add an even better flavor, toast the almonds ahead of time!
4 cubes butter (1 lb)
1/2 C dark Karo Syrup
1/2 C Water
2 C Sugar
1/4 lb chopped almonds (optional)
Chocolate chips or grated chocolate bar (optional)
Melt butter, then add sugar and mix in. Then add all other ingredients into a big fry pan or skillet. When the mixture begins to boil, add almonds (if desired) and turn down heat to medium. Boil and stir constantly at medium heat until it smokes. (Don't mistake smoke for steam. The toffee will turn a nice toffee color. It takes about 10-11 minutes depending on your stove.) When it starts smoking, pour onto a greased pan. Pour chocolate chips or grated chocolate bar over the hot toffee mixture.(if desired) When melted, spread over the toffee. Top with more almonds if desired.