Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking pan.
In a large bowl, mix together the melted butter and brown sugar until smooth.
Add the eggs and vanilla extract, and mix until fully combined.
In a separate bowl, whisk together the flour, baking soda, and salt. Slowly add the dry ingredients to the wet mixture, stirring until just combined.
Fold in the butterscotch chips and toffee bits.
Spread the cookie dough evenly in the prepared baking pan.
Bake for 25-30 minutes, or until the edges are lightly golden.
Allow to cool before cutting into bars and serving.
