Preheat your oven to 350°F (175°C) to ensure it’s hot and ready for your bars.
In a large mixing bowl, combine the softened butter and peanut butter. Use a spatula or electric mixer to cream them together until smooth and fluffy.
Stir in the brown sugar until well combined, then add the egg yolk and mix until fully incorporated.
In a separate bowl, whisk together the flour, quick oats, and salt. Gradually add this dry mixture to the wet ingredients, stirring until just combined.
Gently fold in the semi-sweet chocolate chips and toffee bits, ensuring they’re evenly distributed throughout the batter.
Transfer the mixture to your prepared baking pan, spreading it evenly with your spatula.
Place the pan in the preheated oven and bake for 25-30 minutes, or until the edges are golden brown and the center is set.
Once baked, remove the pan from the oven and allow it to cool in the pan for about 15 minutes. Then, transfer to a wire rack to cool completely before cutting into bars.
