In a food processor bowl or blender container combine raspberries, sugar, lemon juice, and orange juice. Cover and process or blend until smooth. Using a rubber spatula press sauce through a sieve; discard seeds. Set aside.
In a large mixing bowl combine flour, sugar, baking powder, baking soda, and salt. Stir together using a whisk.
In medium bowl whisk eggs until the whites and the yolks are combined. Add sour cream. Whisk until smooth. Stir in milk and melted margarine. Add egg mixture to dry ingredients. Whisk or stir gently just until dry ingredients are wet. (Do not try to remove all the small lumps. The batter should be a little lumpy, not smooth.) Gently fold in chocolate pieces. Set batter aside.
Heat griddle or large heavy skillet over medium heat 3 to 4 minutes or until a few drops of water sizzle when carefully sprinkled on griddle. Pour the teaspoon of cooking oil onto griddle and spread around with heat-safe pastry brush. Stir batter again to distribute chocolate pieces.
For larger pancakes, ladle about 1/3 cup batter per pancake onto hot griddle. For smaller pancakes, ladle a slightly rounded tablespoon of batter per pancake onto hot griddle. Cook for 1 to 2 minutes on the first side or until the pancakes have bubbly surfaces and the edges look slightly dry. Using a wide pancake turner, carefully flip pancakes. Cook 1 to 1-1/2 minutes more on the second side or until golden brown. Remove from the griddle with a pancake turner. (Add additional oil to griddle as necessary to keep later batches from sticking.) Repeat with the remaining batter.
Serve pancakes immediately. Stir sauce and drizzle over pancakes. Top with whipped cream, fresh raspberries, and/or additional chocolate pieces.