Preheat the oven to 180°C.
Place the cauliflower in a blender and process until it resembles fine rice. Heat a large frying pan and add the cauliflower. Dry-fry it for 8-10 minutes until it turns golden brown and soft. Return to the blender and set aside.
In a large saucepan with plenty of boiling water add the bouillon cube. When dissolved, add the pasta and cook following pack instructions. Just before draining the pasta, take ½ cup of pasta water and add to the blender with the cauliflower. Pulse again. Drain the pasta, place it in an ovenproof dish and mix with the blended cauliflower.
Meanwhile, place the breadcrumbs, paprika and butter in a small bowl and mix them well with your hands.
To prepare the cheese sauce, heat the butter in a medium sized saucepan. Add the flour, salt, vegetable powder and mustard powder while whisking continuously. Add the milk and continue stirring to create a smooth cream. Add more milk if needed and then add the cheese. When the cheese has melted and you have a smooth sauce, mix with the pasta and cauliflower.
Top with the buttered breadcrumbs and bake in the oven for 15 minutes until the breadcrumbs turn golden brown.