Preheat oven to 350°.
To prepare stuffing, melt 1 teaspoon butter in a large nonstick skillet over medium-high heat. Add 3 cups onion; sauté 3 minutes. Add 1/2 pound lamb, and cook until browned, stirring to crumble. Remove from heat. Stir in the pine nuts, 2 teaspoons cinnamon, 2 teaspoons allspice, 1/2 teaspoon salt, 1/2 teaspoon pepper, and pomegranate molasses, if desired. Set the stuffing aside.
To prepare the kibbeh, combine bulgur and next 6 ingredients (bulgur through 1 pound lamb) in a large bowl. Press half of kibbeh into bottom of an 11 x 7-inch baking dish coated with cooking spray. Spread stuffing over kibbeh. Press the remaining kibbeh over stuffing. Cut kibbeh into quarters. Press thumb into center of each quarter, leaving an indentation. Place 1/2 teaspoon butter into each indentation. Bake at 350° for 20 minutes. Let stand 5 minutes. Cut each quarter in half.