Preheat oven to 350°. Pierce potatoes with tines of a fork, then bake for 40 minutes or until tender. While potatoes are still hot, peel and mash them finely.
Combine mashed potato, flour, and 1 tsp. salt. Knead until thoroughly mixed and holding together. Roll small amounts into 1" × 6" "ropes". Cut the ropes into 1⁄2" pieces. Use a fork to make an indentation on top of each piece, then pinch between your fingers to plump them up.
To make pesto, pulse pine nuts and 1⁄2 tsp. salt together in a food processor until finely ground. Add garlic and basil and, with the motor running, drizzle in olive oil.
Bring a large pot of salted water to a boil. Place gnocchi in the pot carefully, so that they don't stick together. Cook 2–3 minutes or until gnocchi begin rising to the top. Carefully remove cooked gnocchi from pot with slotted spoon and drain on a plate lined with several thicknesses of paper towel.
Meanwhile, warm the pesto over medium heat in a large skillet. Stir in cheese and cream. Taste for salt. Add gnocchi, stir gently, and serve.