• Heat an electric griddle to 375 degrees F.
• In a large bowl, whisk together the flour, sugar, baking powder and salt. In a separate bowl whisk together 1/2 cup milk, sour cream, eggs, vegetable oil and one teaspoon of vanilla.
• Pour the wet ingredients into the flour mixture and stir together with a spatula until most of the flour is incorporated. Add the sprinkles and mix until batter is free of all flour streaks. The batter will be very thick.
• Swirl a bit of butter under each place on the griddle where you will be dropping the batter. Drop about 1/4 cup of batter onto a hot griddle for each pancake. I used a large cookie scoop for easy release of the batter.
• Cook until the pancake tops are beginning to look dry. You may see a few bubbles, but the batter is thick, so you may not. Flip the pancakes and leave on the griddle until cooked through and light golden brown.

Glaze

• To prepare the glaze, put the remaining tablespoon of butter and three tablespoons of milk in a glass bowl and microwave until melted. Add the vanilla and pinch of salt and whisk. Add powdered sugar, ¼ cup at a time, whisking after each addition. If the vanilla glaze still seems too loose, add a little extra powdered sugar.
• Serve the pancakes topped with glaze and more sprinkles.