Heat a large Dutch oven over medium-high heat with vegetable oil for frying. Get the temperature up to 350 degrees.
In a large bowl combine all of the dry ingredients and stream in club soda until the consistency of a thick pancake batter forms.
Dunk each king crab leg into the batter and gently place in the hot oil and fry until golden brown and crispy roughly 6-7 minutes. Remove from the oil and drain on a sheet tray with a fitted rack. Season with some salt to taste.
In the meantime heat a medium skillet over medium-high heat and melt the butter. Add the sugar and spices into the melting butter and stir to combine. The sugar should begin to caramelize lightly and the spices will become aromatic for about 1-2 minutes.
Pour in the hot sauce and stir everything together. Remove from heat and serve with the tempura king crab legs.
