Preheat oven to 350°F
In a small pan, melt together the butter, brown sugar, honey and red pepper flakes on medium-low heat until everything bubbles together and all the sugar dissolves. This step should take about 5 minutes.
While the sauce is cooking, combine cereal, pretzels, and nuts in a large bowl. Stir to combine.
While it is still hot, pour the sauce over the cereal mixture and stir to combine, making sure that everything is evenly coated.
Spread the mixture onto a lined sheet pan and sprinkle with Maldon salt flakes.
Bake in your preheated oven for 5 minutes, remove from the heat, stir and bake for an additional 5 minutes.
Let the snack mix cool completely before breaking it up into pieces.
Serve in a large bowl or in individual bags, enjoy!