Prepare your ingredients by measuring and chopping the almonds and pecans, and set them aside.
In a heavy-bottom saucepan, combine sugar, water, and corn syrup. Stir gently and bring to a boil over medium heat.
Once boiling, do not stir. Allow to cook, occasionally swirling the pan, until it reaches 300°F (hard crack stage).
Remove from heat and stir in butter, salt, and cinnamon until smooth.
Fold in the chopped almonds until evenly coated.
Pour the mixture onto a baking sheet lined with parchment paper and spread it out evenly.
Melt 2 cups of chocolate chips in the microwave, stirring until smooth.
Pour the melted chocolate over the toffee, spreading it evenly.
Sprinkle chopped pecans over the chocolate, pressing down gently.
Cool completely until the chocolate is set.
Break into pieces and enjoy!