Crush cereal in a food processor or blender, or place in a zip-close plastic bag and crush with a rolling pin; pour into a medium bowl.
Add egg whites, buttermilk and oil to bowl; stir and allow to stand 5 minutes.
Add flour, sugar, lemon zest, baking powder, baking soda and salt to bowl; whisk until well blended. Gently fold in blueberries.
Coat a large skillet with cooking spray; heat over medium-high heat.
To make pancakes, place 3 tablespoons of batter onto skillet; repeat to make 4 pancakes at a time. Cook pancakes until puffed on top, about 2 minutes; flip and cook until golden brown on other side, about 2 minutes more. Repeat to make 12 pancakes. Serve pancakes in a short stack dusted with powdered sugar. Yields 3 pancakes per serving.