Mix together the ingredients for the spiced flour mix in a large bowl and set aside.
Mix the ingredients for the buttermilk mix in a separate bowl and set aside.
Heat the oil in a wide, deep, heavy-based pan (no more than half full), to 175ºC or use a deep-fat fryer.
Place two slices of bread down on a board, spread with a little butter and place 3 slices of orange burger cheese, 2 slices mozzarella and 2 slices of fontina on top of each slice, alternating them as you layer them. Top each with a second slice of bread.
Place a frying pan over a medium heat and when hot, place a sandwich into the pan. Toast until golden - about 3 minutes, then flip over and cook for further 3 minutes on the other side.
Dip the grilled cheese first in the flour mix and next in the buttermilk mix, then back into the four mix. Place the coated sandwich into the hot oil and cook for 3 minutes then turn and cook for a further 2 - 3 minutes, or until golden and crisp.
Whisk cayenne, brown sugar, chilli powder, garlic powder, and paprika in a square pyrex dish then carefully remove about 200ml of the hot oil from the fryer or saucepan. whisk in the reserved frying oil then coat the sandwich with the spicy oil.Serve the sandwich with your choice of sides and enjoy!