Preheat oven to 400 degrees. Line a 12-capacity muffin tin with baking cups.
In a large bowl, whisk together 1 1/3 C cake flour, 1/3 C white cornmeal, baking powder and salt. Set aside.
In a small bowl, mix together 1/4 C sugar, 3 T melted butter, remaining 1/3 C cake flour and 2 T white cornmeal. This is your streusel topping.
In a medium bowl, add the remaining 3/4 C sugar, buttermilk, remaining butter, egg, egg yolk and vanilla bean paste. Whisk to combine.
Pour the wet ingredients into your dry ingredients. Mix to combine. Gently fold in the blueberries.
Scoop the batter into the prepared muffin tins, filling each about three-quarters full. Top each muffin with 1 T of the streusel topping.
Bake for 15 minutes or until a toothpick inserted into the middle comes out clean. Cool in muffin tin for 5 minutes + enjoy warm!
This recipe was inspired by the "Any Berry" Muffins with Cornmeal Streusel from Southern Living Magazine.