Line a 8x8 or 9x9 square pan with parchment paper or foil. Spray with nonstick spray and set aside.
In a 3 quart pot, melt the butter over medium heat. Continue to cook and stir. Keep it on the heat, stirring occasionally, until the foam starts turning golden and the mixture smells nutty.
Stir in 6 cups of marshmallows and the salt. Stir continually until the marshmallows are melted.
Stir in the cereal until just barely coated. Remove from heat.
Stir in 2 cups of mini marshmallows and chopped cranberries.
Working quickly, press half of the mixture into the prepared pan. Top with a handful of marshmallows and whole cranberries, if you want.
Scrape remaining mixture on top and press down.
Top with additional marshmallows and cranberries, if you want.
Let cool at room temperature, then cut into bars and serve.
Keep stored on the counter in a tightly sealed container or ziplock. They are best on the first day.