Over low/medium heat add the first four ingredients to a large saucepan.
Whisk the ingredients until the sugar has melted and everything is combined. Allow mixture to come to a low simmer. Using a spatula scrape the sugar down from the sides of the pan.
Place a candy thermometer into the saucepan. Allow sugar mixture to simmer until it reaches soft ball stage- which is 235 degrees.
Remove pan from the heat and set the thermometer aside.
Stir in the final four ingredients and 1/2 cup of the peanuts until completely melted and combined.
Pour into a buttered 9-inch baking pan and sprinkle the remaining 1/2 cup of peanuts over the top, pressing down slightly. ** I line the pan with parchment paper to make removal easier!
Allow to set up for 2-3 hours or overnight. Place the fudge in the refrigerator for a couple of hours to make slicing into squares easier!