01 -  Fill a large pot with water, salt generously, and bring to a rolling boil for the tortellini. 
 02 -  In a large skillet over medium heat, melt unsalted butter. Add fresh sage leaves and cook, swirling occasionally, until the butter turns golden brown and develops a nutty aroma, about 3 to 4 minutes. Remove sage leaves with a slotted spoon and reserve for garnish. Transfer the browned butter to a small bowl and set aside. 
 03 -  In the same skillet, add olive oil. Sauté chopped shallot until translucent, about 2 to 3 minutes. Add minced garlic and cook for 1 minute until fragrant. 
 04 -  Carefully pour in vodka and let it simmer for 2 minutes to reduce slightly. 
 05 -  Stir in crushed tomatoes, red pepper flakes, salt, and black pepper. Simmer for 8 to 10 minutes, stirring occasionally, until the mixture thickens. 
 06 -  Stir in heavy cream and reserved browned butter. Continue to simmer for 2 minutes, allowing the flavors to meld. Adjust seasoning as needed. 
 07 -  While the sauce simmers, add tortellini to the boiling water and cook according to package directions. Drain thoroughly using a colander. 
 08 -  Add cooked tortellini to the vodka sauce and toss gently to coat. Stir in grated Parmesan cheese until evenly distributed. 
 09 -  Serve immediately, garnished with crispy sage leaves and extra Parmesan as desired.