AngiesSouthernKitchen.com and ForkAndGood.com both have good recipes for old-fashioned toffee. Both these recipes require a candy thermometer, a baking tray, parchment paper and a heavy-bottomed saucepan.
To make Fork and Good's toffee, line a baking sheet with greaseproof paper. In a large saucepan, combine 1 3/4 cups of caster sugar, 1 cup dark brown sugar, 1 1/4 golden corn syrup and 1 1/3 cups of unsalted butter. Add 2 cups whipping cream and 1 cup evaporated milk. Cook on high heat until the butter melts and the sugar dissolves, stirring constantly.
Monitor the mixture with a sugar thermometer and continue stirring until the temperature reaches 245 degrees Fahrenheit. Remove from heat, then stir in 2 teaspoons of vanilla extract and pour the mixture onto the baking tray. Allow it to cool for several hours, then cut into squares.
For Angie's Southern Kitchen's old-fashioned English toffee, roughly chop 2 cups of raw almond out of a 1 pound bag. Grind the remaining almonds into a coarse meal and spread them over a parchment-lined baking sheet. In a heavy-bottomed saucepan, melt 1 pound unsalted butter with 1 teaspoon salt, stirring constantly. Add 2 cups of sugar, continuing to stir. When the sugar has dissolved, add 1 tablespoon water and 1 tablespoon light corn syrup. When a candy thermometer reads 280 degrees Fahrenheit, add 2 tablespoons vanilla extract and the chopped almonds.
Continue cooking until the mixture reaches 300 degrees F, then remove from heat and continue stirring for about 5 minutes. Pour the mixture onto the almond-covered baking sheet. Top with 12 ounces chopped chocolate. Refrigerate for at least 30 minutes, then break into pieces.