Preheat oven to 375 degrees F (190 degrees C).
Into a mixing bowl, add Granulated Sugar (1/3 cup), All-Purpose Flour (1/2 cup), Ground Cinnamon (1 teaspoon), and Salt (1/4 teaspoon). Mix to combine.
Add Butter (4 tablespoon) and mash with a fork until mixture has a crumbly texture.
In a separate mixing bowl, add All-Purpose Flour (2 cup), Salt (1/2 teaspoon), and sifted Baking Powder (2 teaspoon). Mix and set aside.
In a third mixing bowl, add Granulated Sugar (3/4 cup), Butter (4 tablespoon), and Large Egg (1) Combine with a hand mixer until smooth.
Add Vanilla Extract (1 teaspoon). Mix to combine.
Add the dry ingredients into the wet mixture 1/3 at a time. Combine with a hand mixer. Add Buttermilk (1/2 cup) for additional moisture. Keep mixing until smooth.
Add Fresh Mixed Berries (2 cup). Fold in to the mixture carefully. Do not over mix.
Transfer the batter into a cake pan lightly dusted with flour.
Sprinkle the crumbly mixture over the top.
Bake for 35-45 minutes, or until a toothpick inserted into the center of the dish comes out clean.
Allow to cool for a couple of minutes and remove from the pan. Serve!