Preheat oven to 400 degrees.
Place bacon on a rack over a cookie sheet and cook until crispy, about 15 minutes. Reserve bacon fat. The recipe calls for 8 tablespoons of butter (fat) – replace as much of butter as you have bacon fat. Once bacon is done, drain on paper towels and chop into bits.
Place the sugar and maple syrup in a large, heavy saucepan over high heat and stir with a wooden spoon until sugar begins to melt. Lower the heat to medium-high and keep stirring just until the sugar is melted. Stop stirring and watch for it to turn a medium caramel color. About 10 minutes total.
Stir in peanuts, and then bacon fat and butter. Then add Old Bay, cayenne and dry mustard. Allow peanuts to cook for about two minutes, stirring constantly. Stir in the bacon.
Turn the mixture out onto a sheet pan lined with parchment paper, and spread it evenly to the desired thickness with a wooden spoon or stiff rubber spatula. Sprinkle salt on top, while brittle is still warm.
Allow to cool completely--at least one hour--then break the brittle into pieces and store in an airtight container at room temperature. If your brittle isn't brittle enough to break into pieces, pop it in the freezer for 10 to 15 minutes, until it hardens enough to snap easily.