Preheat oven to 425 degrees F. Grease and flour a standard madeleine pan, set aside. Alternately, you could also use a mini muffin pan.

In a large bowl, whisk together the cornmeal, flour, sugars, baking soda and salt until evenly combined. Make a well in the center of the dry ingredients and add in the egg, buttermilk, oil and vanilla. Stir until just combined. Fold in the blueberries and then add about a rounded tablespoon of batter into each cavity of the prepared pan.

Bake until puffed up, golden brown and the cookies spring back when you lightly touch them, about 10 to 12 minutes. Remove from the oven and let cool for about 5 minutes before inverting the cooking onto a wire rack to cool completely. Clean out, dry and re-grease the pan to bake off the remaining batter. Cookies can be kept in an airtight container at room temperature for up to 2 days. Enjoy!