Add silken tofu to a food processor, and pulse until it’s in a grainy texture.
Pour in yogurt, 2/3 cup of soymilk, and cheddar cheese and process until smooth. Some graininess is acceptable, but if the mixture looks dry, add a little more milk. Cook macaroni according to package, and drain.
Add butter to pot with macaroni and stir over low heat until butter is melted.
Stir in all of the cheese sauce and stir until heated and melted, about 5 minutes.
