• Preheat your oven to 350°F. Grease a 9-inch springform pan and line the bottom with parchment paper. Set it aside.
• For the filling: Mix cream cheese, sugar, and vanilla on medium-low speed until creamy. Add an egg white and mix on low to combine. Set this mixture aside.

For the cake batter:

• In a bowl, stir together flour, baking powder, baking soda, and salt. Set this mixture aside.
• Using an electric mixer, cream together butter and sugar at medium-low speed. Add an egg, an egg yolk, and vanilla. Slowly mix in the flour mixture, alternating with sour cream. Transfer the batter to the prepared pan and smooth it with a spatula. Sprinkle 1/3 cup blueberries on top. Spread the cream cheese filling over the batter, and then place the remaining blueberries on top.

For the topping:

• Combine sugar, flour, and chilled cubed butter in a bowl.
• Stir with a fork or pastry blender until the mixture is crumbly, ensuring the streusel is in pea-sized crumbs.
• Sprinkle the streusel on top of the blueberries and bake for 40-45 minutes until a cake tester inserted in the center comes out clean. If it starts browning too much, cover the top with aluminum foil.

After baking:

• Cool the cake on a rack.
• Run a thin knife around the cake to loosen it from the springform pan.
• Store it in the fridge.