HEAT oven to 400ºF.
COOK pasta as directed on package, omitting salt. While pasta is cooking, spread tomatoes onto baking sheet; brush with oil. Sprinkle with pepper. Bake 10 min.
MEANWHILE, blend sour cream and nuts in blender until smooth. Add spinach, 1 cup at time, blending after each addition until smooth.
DRAIN pasta; place in large bowl. Add spinach mixture; toss to coat. Spoon onto platter; top with tomatoes and cheese.