Cook the macaroniin a large pot of salted boiling water for 8 to 12 minutes until al dente (tender). Drain well.
Meanwhile, heat a large saucepan over medium heat. Cook bacon, stirring, for 5 mins or until crisp. Use a slotted spoon to transfer to a bowl. Add butter to the pan and stir until butter melts. Add thepaprika and cook, stirring, for 30 secs or until aromatic. Add theflour and cook, stirring, for 1 min or until the mixture is slightly grainy. Add the milk and use a balloon whisk to stir until well combined. Cook, stirring with a wooden spoon, for 5-7 mins or until mixture boils and thickens. Remove from heat. Stir in half the bacon, parmesan, spring onion and three-quarters of the cheddar. Season.
Preheat grill on medium. Stir macaroni into sauce. Spoon evenly among six 1 1/2-cup (375ml) ovenproof dishes.
Top with remaining bacon and cheddar. Cook under grill for 2 mins or until golden and heated through.