Bring a pot of water to a rolling boil over high heat. Remove creamed spinach pouch from the box and place pouch in boiling water. Boil until heated through, 35 to 40 minutes, rotating serving times during heating.
Meanwhile, fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the rotini, and return to a boil. Cook uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 8 minutes. Drain well in a colander set in the sink.
Combine garlic, olive oil, and tomatoes in a large bowl. Stir in the heated creamed spinach. Serve over rotini.