Cook pasta as directed on package. Drain. Meanwhile, in food processor, combine beans and 1/4 cup of the milk. Cover; process 30 to 60 seconds or until completely smooth. In large saucepan, mix pureed beans, remaining milk, onion powder, mustard, salt and pepper with wire whisk. Cook until mixture starts to boil, stirring frequently. Reduce heat to low and stir in all cheese until melted. Combine cooked pasta and sauce. Let stand 5 minutes. (Mixture thickens as it stands.) Sprinkle with paprika if desired.