In a large bowl, whisk together the flour, cake mix, sugar, baking powder, and salt. In a medium bowl, whisk together the milk, oil, eggs, and vanilla.

Pour the wet ingredients into the dry ingredients. Stir until just combined (small lumps are okay) and let sit 10 minutes. Gently stir the sprinkles into the pancake batter.

Preheat a griddle or large skillet over medium heat. Lightly butter the preheated griddle and pour the batter by 1/4 cup scoops onto the griddle (I always use a measuring cup so they're all the same size).

Cook 3-4 minutes or until there are bubbles throughout the top of the pancakes, and the edges of the pancakes look dry. Flip the pancakes and cook for another minute or until lightly browned on the bottom.

Serve warm with whipped cream and additional sprinkles, if desired.