For the Spicy Ketchup, mix together ketchup and hot sauce in a small bowl. Refrigerate and serve with Corndog Mac & Cheese
For the Mac and cheese, heat the oven to 400F (205C) and spray an 8-inch square (20 cm) baking pan with non-stick cooking spray.
Scatter half the cooked macaroni noodles into prepared pan followed by half the cheese. Top with the remaining noodles and cheese; set aside.
Whisk together milk, eggs, mustard powder, salt and pepper in a medium bowl. Pour mixture over noodles and cheese and bake until set, about 30 to 35 minutes.
Remove to cooling rack to cool completely. Place in fridge to chill for 2 hours.
To assemble, line a rimmed baking sheet with a wire cooling rack; set aside. Heat oven to 200F (93C).
Cut mac and cheese in half and cut each half onto eight 1x4-inch (2x10cm) sticks.
Place sticks into a shallow dish and toss with ¼ cup flour (30g); set aside.
Whisk together remaining flour, cornmeal, baking powder, salt, pepper and sugar in a large bowl. Add milk and egg and whisk to combine.
Heat 2-inches (5 cm) of oil to 350F (176C) in a large Dutch oven or heavy bottomed saucepan over medium-high heat.
Dip mac and cheese sticks in batter and fry in batches of two until golden, about 2 to 4 minutes, flipping halfway. Transfer to prepared rack and place in oven to keep warm while frying remaining sticks. Serve with Spicy Ketchup.