Cook pasta al-dente according to package directions.
In a large skillet over medium-high heat, melt butter and add onion. Cook until fragrant and onions become translucent in color.
Add garlic and oregano, salt, pepper, and red pepper flakes and cook, stirring frequently for 1 minute.
Add pasta sauce, stir to combine. Cook for 3-4 minutes, stirring frequently until the pasta sauce is heated through.
Add heavy cream and stir to combine well.
Remove from heat and stir in cooked pasta until coated completely.
Garnish with Parmesan and fresh chopped parsley and enjoy!