Gather your equipment and ingredients so that you have everything close at hand on the counter or table.
Prepare the Ingredients and Baking Pan
Lightly butter a quarter sheet or cake roll baking pan. (If you don't have a quarter sheet pan, you may use an oblong cake pan, or even part of a regular baking pan.)
Using a nut chopper, measure out and coarsely chop the pecans.
Spread half of the chopped pecans in a lightly buttered quarter sheet baking pan. Sprinkle half of the semi-sweet chocolate chips over the chopped pecans.
Cook the Toffee
In a large saucepan, melt butter. Stir in granulated sugar, water, and light corn syrup. Bring mixture to a boil over medium heat. Continue boiling and occasionally stirring until mixture nearly reaches hard-crack stage (I cooked mine to 290 degrees on a candy thermometer). This process may take 10-15 minutes.
When the syrup has nearly reached hard ball stage, remove from heat and pour the syrup over the pecans and chocolate chips.
Immediately top with remaining chocolate chips and then the remaining chopped pecans.
Wait 4-5 minutes, then gently press down with a rubber spatula to spread the chocolate evenly.
While the candy is still warm, loosen it from the baking sheet. When cool, break into chunks. Makes 30-36 pieces of candy.
Notes
*Unless otherwise indicated, all butter used on this recipe site is salted.