Instructions: 

1. Preheat oven to 350 degrees. Put hazelnuts on a baking sheet and toast in oven until light brown and fragrant, about 5-7 minutes. Cool completely and then coarsely chop.
2. In a small saucepan, melt the butter. When butter starts to sizzle, tear sage leaves into the pan and fry for about 20 seconds. Remove from the heat.
3. Meanwhile, cook ravioli in 4 quarts of water for each pound. Add a hearty pinch of salt. Bring water to a full boil, reduce heat and then add ravioli. (If you add ravioli when the water is at a robust boil, you risk having the ravioli split open.) Occasionally, stir gently to prevent ravioli from sticking to the bottom of the pot. Once water returns to a gentle boil, cook about 8-12 minutes. Drain carefully, or simply use a slotted spoon to remove the ravioli individually from the pot.
4. Pour butter sauce over ravioli and sprinkle with toasted hazelnuts. Serve immediately.