In a large bowl, whisk together flour, baking powder, sugar, salt and cake mix. Set aside.
In a separate small bowl, mix together oil, eggs and milk. Slowly add the wet ingredients into the dry ingredients. Mix just until combined. Stir in sprinkles. Batter will be thick. You can add more milk to thin it out, if desired.
Heat a griddle over medium-low heat. Grease with cooking spray. Ladle the pancake batter onto the hot pan and cook pancakes for about 2 minutes on each side.
Frosting
In a medium bowl, whisk together all the frosting ingredients until creamy and combined. Thin with more milk, as needed.
Drizzle frosting over warm pancakes. Serve immediately and enjoy!