Preheat oven to 325 degrees. Line a baking sheet with parchment paper and set aside.
Place all of the ingredients into a large mixing bowl. Mix all together until just combined.
Pour mixture onto parchment-line large baking sheet and spread as thin as you can get it - I used as wooden spoon to mix all and spread mix into pan.
As my brittle was still too soft the day I made it, I preheated the oven to the 325 degrees, turned the oven off and put my pan of brownies back in for a few minutes to crisp up the too-soft brownie pieces.
Best to cut into pieces while the brittle is still warm. I used a pizza cutter. when completely cool, break into those pieces.