How to Make It
Sift together flour, cornmeal, sugar, baking powder, baking soda, and salt in a small bowl. Stir together buttermilk, butter, and eggs in a large bowl. Stir flour mixture into milk mixture.
Heat 1 tablespoon of the oil in a large nonstick skillet over medium. Coat inside of a 3-inch round cookie or biscuit cutter with cooking spray. Place in hot skillet; spoon 1 1/2 tablespoons of batter into cookie cutter. Cook until just set, 45 seconds to 1 minute. Remove cookie cutter. Cook pancake until golden brown on the edges; turn pancake, and cook another 90 seconds. (You can do up to 4 at a time. As soon as you remove the cookie cutter, start on the next pancake.) Place cooked pancakes on a baking sheet, and keep warm in a 225°F oven. Repeat process with remaining oil and batter, to make 32 pancakes.
To assemble stacks, place 1 pancake on each of 8 plates. Layer each with 2 teaspoons of the blueberry jam, 1 pancake, 2 teaspoons of the mascarpone, 1 pancake, 2 teaspoons of the cherry preserves, 1 pancake, and 2 teaspoons of the mascarpone. Top each with about 3 blueberries.