In a medium bowl, combine ricotta cheese, dried plums, parmesan cheese, garlic and pepper. Set aside. For each ravioli, brush edges of 1 wrapper with egg white. Place 2 teaspoons plum mixture onto center. Fold diagonally in half to form a triangle; seal edges, pressing to remove any air pockets. Repeat with remaining filling and wrappers. Refrigerate on wax paper lined baking sheet until ready to cook(up to 2 hours).
Meanwhile, in small saucepan, cook butter and sage over medium high heat until butter begins to turn brown. Remove from heat and keep warm. In large saucepan, add half of the ravioli to boiling water. Cook 3 to 4 minutes or until tender. Using a slotted spoon, remove ravioli to individual serving bowls. Repeat with remaining ravioli. Drizzle each serving with sage butter.