Serve pancakes immediately, with a generous drizzle of sprinkle sauce.
Pancakes:
1 cup all-purpose flour
2 tablespoons white sugar
1 teaspoon baking powder
½ teaspoon baking soda
½ teaspoon salt
1 cup buttermilk
1 egg
2 tablespoons butter, melted
1 ½ teaspoons vanilla extract
¼ cup sprinkles
Sprinkle Sauce:
1 cup confectioners' sugar
⅓ cup heavy whipping cream
1 teaspoon vanilla extract
⅛ teaspoon sea salt
2 tablespoons sprinkles
cooking spray
Whisk flour, sugar, baking powder, baking soda, and salt together in a bowl.
Combine buttermilk, egg, butter, and 1 1/2 teaspoon vanilla extract in a separate bowl. Beat to break up the egg. Pour over the flour mixture; stir until just combined. Stir 1/4 cup sprinkles gently into the batter. Allow batter to rest for 5 minutes.
Whisk confectioners' sugar, heavy cream, 1 teaspoon vanilla extract, and salt together in a small bowl until smooth. Add 2 tablespoons sprinkles.
Heat a large nonstick skillet over medium-low heat; coat with cooking spray. Drop 1/2 cup batter into the skillet. Spread with the back of a spoon to about 1/4-inch thick. Cook until bubbles form and the edges are dry, 2 to 3 minutes. Flip. Cook until second side is set, 1 to 2 minutes. Transfer to a plate. Repeat with remaining batter.
Stir sprinkle sauce so sprinkles rise to the top. Serve pancakes with a generous drizzle of sprinkle sauce.