In a large bowl, stir together all-purpose flour, whole wheat flour, Carnation Breakfast Essentials(R) Rich Milk Chocolate Light Start(TM) Rich Milk Chocolate Powdered Drink Mix , cinnamon, baking powder, and salt. In another bowl, whisk together eggs, milk, oil, and vanilla until combined. Add egg mixture all at once to flour mixture. Stir just until moistened (batter should be slightly lumpy). Stir in chocolate pieces. For thinner pancakes, add in additional milk until desired consistency.
Pour 1/4 cup portions of batter onto a hot, lightly greased griddle or heavy skillet. Cook over medium heat for 1 to 2 minutes on each side or until pancakes are golden brown; turn over when surfaces are bubbly and edges are slightly dry.
Serve warm. If desired, dust pancakes with powdered sugar or serve with yogurt or fresh fruit.