Using a medium bowl, add flour, cornmeal and brown sugar; stir until well combined.

Using a pastry blender (or two table knives), cut the butter into the flour mixture until it’s the size of small peas; set mixture aside.

Preheat oven to 350°F.

Spray a 9” or 10” cast iron skillet with nonstick baking spray; set skillet aside.

Using an electric mixer, cream together butter and sugar until light and fluffy (3-4 minutes on medium speed).

Add eggs and vanilla extract; mix on low speed until well combined. (Tip: Make sure to scrape sides of bowl.)

In a separate bowl, sift together flour, baking powder and salt. Add half of the flour mixture to the bowl; mix on low speed until well combined.

Add buttermilk; mix on low speed until well combined.

Finally, add remaining flour mixture and mix on low speed until well combined.

Using a small bowl, stir together lemon juice and cornstarch. Add blueberries and stir until well combined.

Spread ¾ of the batter into the prepared skillet. Spread blueberry mixture on top and then spread remaining batter on top of blueberries.

Sprinkle streusel mixture on top of batter.

Bake at 350°F for 65-70 minutes or until top of cake is light golden brown in color.

Let cake cool for 20 minutes before slicing.

Using a small bowl, whisk together powdered sugar and milk. Drizzle cake with glaze before serving.