• Preheat oven to 325 degrees F. Grease 8-inch springform pan and line the bottom with parchment paper. Set aside.

To make the cream cheese filling

• In a stand mixer, or with an electric mixer, combine the cream cheese, sugar and vanilla on medium-low speed until creamy. Add egg white and mix on low just to combine. Set aside.

To make the cake batter

• In a bowl whisk together flours, xanthan gum and salt, set aside.
• Cream together the butter and sweetener on medium-low speed. Add egg and egg yolk and vanilla.
• Slowly mix in the flour mixture alternating with the sour cream.
• Transfer the batter into the prepared pan and smooth with a spatula. Sprinkle with 1/3 cup blueberries. Spread the cream cheese filling on top. Place remaining blueberries over cream cheese filling.

To make the topping

• Combine the sweetener, almond flour, cinnamon, nutmeg and butter in a bowl. Mix well.
• Sprinkle the streusel on top of blueberries.
• Gently press into the batter slightly and bake for 40-45 minutes until a cake tester inserted in the center comes out clean.
• If it starts browning too much, tent the top with aluminum foil.
• Cool completely in the pan on a rack, run a thin knife around the cake and loose ring of springform pan.
• Store the cooled cake in the refrigerator.