Buttermilk Pancakes with Blueberry Syrup

Name: Buttermilk Pancakes with Blueberry Syrup
Ingredients: 3 tablespoons unsalted butter, plus more for griddle; 3 large eggs; 2 1/4 cups well-shaken buttermilk; 2 1/4 cups all-purpose flour; 3 tablespoons sugar; 1 teaspoon baking powder; 1 teaspoon ground cardamom; 1 teaspoon pure vanilla extract; 3/4 teaspoon baking soda; 1/2 teaspoon ground cinnamon; 1/2 teaspoon kosher salt; Vegetable oil, for griddle; Blueberry Syrup, recipe follows; 1 1/2 cups real New York State maple syrup; 1 cup blueberries