Cook the tortellini according to package instructions in a large pot of salted boiling water; drain or keep warm for adding to sauce later.
Heat the olive oil and butter in a large stainless steel skillet over medium heat.
Add the diced onion and cook, stirring, until soft and translucent, about 3–4 minutes.
Add the minced garlic and cook about 1 minute until fragrant.
Stir in the crushed tomatoes (including juices) and add salt, pepper, garlic powder, onion powder, red pepper flakes, thyme, oregano, cumin, dried basil, and raw sugar. Bring to a simmer and cook about 5 minutes.
Add the fresh spinach all at once, cover the pan, and let it wilt, stirring occasionally; add water 1/4 cup at a time if the sauce becomes too dry.
In a small bowl whisk together the flour, milk, and heavy cream until smooth, then pour this mixture into the tomato-spinach sauce and stir to combine.
Stir in the grated Parmesan until melted and incorporated.
Using a slotted spoon or spider, transfer the cooked tortellini to the sauce and gently fold to coat, being careful not to tear the pasta. Heat until everything is warmed through.
Serve immediately with additional Parmesan and fresh basil if desired.