Step 1

Preheat oven to 350º F and lightly grease a 12x17-inch jelly roll pan with butter or non-stick spray.

Step 2

Spread graham crackers or saltine crackers out in an even layer in greased jelly roll pan.

Step 3

In a medium saucepan over medium heat, combine butter and brown sugar and cook, stirring frequently until butter is melted and sugar has dissolved. Bring mixture to a boil and cook for 2-3 minutes, stirring continuously, then reduce heat to a simmer and cook for another 1-2 minutes.

Step 4

Remove mixture from heat and stir in vanilla extract and salt, whisking until incorporated.

Step 5

Pour caramel mixture in an even layer on top of graham crackers or saltines, smoothing as necessary.

Step 6

Sprinkle chopped pecans on top of caramel layer, then place baking sheet in oven and bake for 7-9 minutes, or until caramel/toffee mixture becomes bubbly.

Step 7

Remove from oven and let cool for 5 minutes.

Step 8

Sprinkle chocolate chips on top of hot toffee and let sit 2 minutes before melting, then spread into an even layer.

Step 9

Let cool, then cut or break into pieces. Store in an air-tight container at room temperature or in the freezer.