Prepare pasta according to package directions or until al dente, drain.
Heat 1 teaspoon olive oil in a saucepan, add sausage and cook until browned for about 2 minutes. Set aside.
Heat 2 tablespoons olive oil, then saute onion and garlic over medium heat until tender.
Add anchovy paste and cook for about 30 seconds.
Add tomatoes, sugar, italian seasoning, salt and pepper to taste.
Bring to boil until the sauce is evaporated and thicken for about 4-5 minutes.
Reduce the heat to low, stir in whipping cream and butter. Cook for 2 more minutes
Add the cooked pasta, cooked sausage and spinach. Cook for 2-3 more minutes.
Remove from the stove and serve immediately.