Preheat oven to 375 degrees F. In large saucepot, prepare spaghetti in boiling salted water as label directs.
Meanwhile, in blender at low speed, blend ricotta, Romano, eggs, egg yolk, pepper, nutmeg, 1/2 cup milk, and 1/2 teaspoon salt until smooth.
Drain pasta and return to saucepot. Add ricotta mixture, bacon, and remaining 1 1/2 cups milk, stirring to combine.
Transfer pasta mixture to 2 1/2-quart baking dish (about 2 inches deep). Bake 35 to 40 minutes, until golden around edges and almost set but still slightly liquid in center. Let pie stand 10 minutes before serving (liquid will be absorbed during standing). Cut into wedges to serve.