PANCAKES: Combine flour, cake mix, sugar, baking powder and salt in a bowl and mix. Add milk, eggs, and vanilla extract. Stir until smooth. Fold sprinkles into batter.
Preheat a griddle/skillet to medium heat. Butter or spray griddle/skillet with cooking spray. Pour 1/4 cupfuls of batter onto griddle/skillet and cook until bubbles form on top, about 2-3 minutes. Flip and cook for 1 minute more. Serve with vanilla glaze.
VANILLA GLAZE: Combine confectioners' sugar, butter, vanilla and milk to form glaze. You may need to add a little more milk to reach desired consistency. Stir in sprinkles. Drizzle over warm pancakes.