Fill large pot with water. Bring water to gentle boil over medium-high heat.
In medium bowl, stir ricotta cheese, Parmesan cheese, thyme, orange zest and pepper.
Place four wrappers flour sides down on cutting board. Spoon 1 1/2 tablespoons cheese mixture onto center of each wrapper. Using back of spoon, press down on cheese mixture to create well about 1 1/2 inches across (width of large egg yolk), leaving at least 1/2 inch space around edges of wrapper. Without breaking it, carefully place one egg yolk in center of each well.
Using pastry brush, brush edges of wrappers with egg white. Place one top wrapper with flour side up on each bottom wrapper. Using thumbs and forefingers, firmly press edges together to tightly seal each ravioli. Set aside.
Using slotted spoon or spatula, carefully drop each ravioli into boiling water. Cook 2 1/2-3 minutes, or until wrappers are al dente (cooked not too soft but not overdone). Using slotted spoon, gently remove raviolis from pot, draining well. Transfer to plates. Drizzle with oil. Sprinkle with almonds, sage and bell pepper, if desired.