Place 1/2 C pecans, 1/8 C brown sugar, 1 T cocoa powder, 1/2 t cinnamon, and 1/8 C chocolate chips in a food processor and grind together to make a rough powder.
Preheat a conventional oven to 350°F. Place butter, sugar and vanilla bean in a mixer and cream until soft and fluffy. Add the egg and egg yolk one at a time until they are well incorporated into the creamed mixture. Combine all of the dry ingredients in a mixing bowl. Add ½ of the dry ingredients and ½ of the crème fraîche to the creamed mixture and continue mixing until all the ingredients are combined well. Add the remaining dry ingredients and remaining crème fraîche and mix until all the ingredients are combined. Line an 8" x 8" metal pan with parchment paper. Layer half of the cake batter into the lined pan. Spread the 2 cups of blueberries on top of the cake batter in a neat layer. Sprinkle half of the pecan streusel over the blueberries. Next, carefully spread the remaining half of the cake batter and top with the remaining streusel. Bake for approximately 35 minutes or until the cake springs back to touch in the center of the cake.
Place 4 C blueberries, 1/2 C, confectioners sugar, and 1 vanilla bean, split and scraped, in a saucepan over medium heat. Cook until the berries start to give off a little juice and are glossy.
Cornbread Ice Cream
Place the corn in a saucepan and heat to remove any water from the freezer. Pour off any excess water. Add the milk, cream and ½ C sugar and bring to a boil. Place the remaining sugar, egg yolks and salt in a bowl and whisk together. Remove the saucepan from the heat and gently fold in the egg yolk mixture. Mix all ingredients together with an immersion blender. If you do not have an immersion blender you can mix together with a whisk. Strain this mixture and let it cool. Process in an ice cream machine.
Preheat a conventional oven to 200°F. Place the freeze dried corn, almond flour, cake flour and salt in a food processor and mix together until all ingredients are combined well. Drizzle in the melted butter and mix until you have a dry, crumbly mixture. Spread the cornbread streusel over a cookie sheet and bake for approximately 10-15 minutes. Streusel should be toasty without taking on any color.
Place a piece of the cake in the center of a plate. Sprinkle some corn streusel around the cake. Top with warm blueberries and a scoop of cornbread ice cream.