A.C.
You got it! This is a really good toffee recipe! Don't be scared of a candy thermometer, you can't make good toffee without one (unless you use the glass of water method which is much less precise!) This is actually very easy to make.
Toffee
2 c butter (1 lb)
1/2 c water
1/4 c light corn syrup
2 1/2 c sugar
Butter a 12x18" baking sheet.
In a heavy 3qt saucepan combine butter, water, corn syrup & sugar. Place over high heat and stir with a wooden spoon until mixture comes to a boil. Continue stirring until it begins to thicken. Reduce heat to low and stop stirring. Clip on candy thermometer and cook syrup to 300 degrees (no matter how it looks). Don't let the thermometer touch the bottom of pan. Remove from heat and pour into baking sheet. Let cool 1 hour.
At that point, if desired, melt 1 lb milk chocolate and spread over top of toffee then sprinkle warm chocolate with 4 c chopped nuts (sliced or slivered almonds, chopped pecans or walnuts). Press lightly so nuts adhere. Allow to stand room temp for 24 hours. Break into irregular pieces and store in an airtight container. Makes 4-5 lbs (about 150 pieces).
If you run into the problem of separation during cooking, add about 1/2 c hot water and stir well. This will save your batch of toffee. Your neighbors are going to LOVE you!