Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper and arrange the graham cracker sheets in a single layer, covering the entire sheet.
In a medium saucepan, combine the unsalted butter and light brown sugar. Cook over medium heat, stirring constantly until the butter is melted and the mixture is smooth and bubbly. This should take about 3-5 minutes.
Remove the saucepan from the heat and stir in the peanut butter until it’s fully incorporated.
Carefully pour the peanut butter toffee mixture over the arranged graham crackers, spreading it evenly to cover all of them.
Place the baking sheet in the preheated oven and bake for 8-10 minutes, or until the mixture is bubbly and golden.
Remove the baking sheet from the oven and immediately sprinkle the semi-sweet chocolate chips over the hot toffee. Allow them to sit for a couple of minutes to soften, then use a spatula to spread the melted chocolate evenly over the top.
Sprinkle the chopped roasted salted peanuts over the melted chocolate, pressing them down gently to ensure they stick.
Allow the toffee to cool at room temperature for about 30 minutes, then place it in the refrigerator for an additional 30 minutes to set completely. Once set, break or cut into pieces and enjoy!