Prepare Ravioli according to directions on package.

To make the sauce:

1. Heat a saute pan over medium-high heat and, when hot, add the butter and let it melt in 1 spot. (Do not move the pan.)
2. When the butter has begun to brown around the edges, pick up the saute pan and swirl to keep the melted butter from burning and to melt the remaining butter.
3. Add the sage leaves and reduce the heat to medium.
4. Continue to cook until the leaves are crispy, 1 to 2 minutes.
5. Season with salt and pepper.  
6. Plate ravioli and drizzle with sauce.
7. Garnish with the crispy sage leaves.
8. Sprinkle with Parmigiano-Reggiano and serve.