Preheat the oven to 325°F and line a 9 or 10 inch springform pan with parchment paper on the bottom and grease the sides of the pan well. Set aside.
Make the crumble. In a large bowl combine the butter, granulated sugar, brown sugar, flour, and salt. Use a fork or your fingers to mix together until the mixture clumps together and resembles wet sand.
Press about ⅔ of the mixture into the prepared pan, pressing it firmly into an even layer to form the crust of the cheesecake. Set the pan and the remaining crumb topping aside.
Make the cheesecake. Whip the softened cream cheese, room temperature sour cream, and granulated sugar together in a stand mixer with the paddle attachment for 2 minutes until smooth and creamy. Add the vanilla extract and then the eggs one at a time, beating until just combined.
Pour the cheesecake batter over the crust in the prepared pan. Drop the pan on the counter a few times to get rid of any air bubbles. Top with the blueberries, evenly spacing them all over the top of the cheesecake. Top the blueberries with the remaining crumble topping, squeezing it in your palms into bigger and smaller pieces of crumble.
Carefully place in the middle rack of the oven and bake for 1 hour, rotating the cheesecake halfway. The cheesecake will still be wobbly in the center when done, which is correct.
When the cheesecake is done cooking, turn off the oven and open the door to the oven slightly. Leave the cheesecake in the turned off oven for an hour to allow it to cool down gradually.
After an hour, take it out of the oven, run a knife along the edges to release from the pan and set on a cooling rack for 1 hour to come to room temperature. Cover the cheesecake with tinfoil and place it in the fridge to set overnight.
When ready to serve, release the springform pan and remove the rim of the pan carefully. If using, make the vanilla glaze by combining the powdered sugar, milk, vanilla extract and salt in a small mixing bowl and whisk to combine. Drizzle all over the cheesecake. Slice into 16 servings and enjoy!