4 cups pecans — finely chopped
1 pound butter
1/2 cup water
1/4 cup light corn syrup
2 1/2 cups sugar
1 pound milk chocolate
Butter a 12×18 baking sheet; cover with pecans and set aside. In a heavy 3 qt saucepan, combine butter, water, corn syrup, and sugar. Place over high heat and stir with a wooden spoon until mixture comes to a boil. Continue stirring until mixture begins to thicken. Reduce heat to low; remove wooden spoon.
Clip on candy thermometer. Cook syrup to 290F or soft crack stage. Remove from heat immediately and pour over pecans. Cool at room temperature for 1 hour.
Melt chocolate. Spread over the top of the toffee. Sprinkle warm chocolate with nuts if desired- pressing lightly so they adhere.
Allow to stand at room temperature for 24 hours. Break into irregular pieces and store in an airtight container. Makes 4-5 pounds- or around 150 pieces.