courtesy of Epicurious.com

Sweet Potato Ravioli Ingredients
1 1/2 pounds sweet potatoes (yams)
2 tablespoons (packed) golden brown sugar
1/4 teaspoon ground nutmeg
48 square wonton wrappers
2 large egg whites, beaten until foamy


Brown Butter Sauce
3/4 cup (1 1/2 sticks) butter
1 1/2 tablespoons balsamic vinegar
1 1/2 tablespoons chopped fresh thyme
Chopped toasted pecans (optional)

Method

1. Pierce potatoes all over with fork. Bake potatoes until soft throughout. Cool slightly. Cut potatoes in half; scoop 2 packed cups potato flesh into large bowl. Mix in brown sugar and nutmeg. Season sweet potato filling with salt and pepper.
2. Line large baking sheet with plastic wrap. Place 1 wonton wrapper on work surface. Using pastry brush, lightly brush wrapper with beaten egg whites. Place 1 tablespoon sweet potato filling in center of wrapper. Top with another wrapper. Press edges together to seal. Transfer to prepared baking sheet. Repeat with remaining wrappers and filling. (Can be made up to 4 hours ahead. Cover and refrigerate.)
3. For brown butter sauce: Melt butter in heavy large skillet over medium heat. Cook until butter begins to brown, about 4 minutes. Remove from heat. Carefully mix in vinegar and thyme.
4. Meanwhile, working in batches, cook ravioli in large pot of boiling salted water until just tender, about 3 minutes. Using slotted spoon, carefully transfer ravioli to hot butter sauce; spoon sauce over to coat ravioli. Transfer to plates. Sprinkle with pecans, if desired; serve immediately.