In a medium bowl, combine all-purpose flour, granulated sugar, dark brown sugar, and cinnamon. Cut in softened butter until the mixture resembles coarse crumbs. Set aside.

Preheat your oven to 175ºC (350ºF) and grease a springform pan. In a large mixing bowl, cream together the butter and granulated sugar until light and fluffy, about 3-5 minutes.

Add the room-temperature eggs one at a time, mixing well after each addition. Scrape down the sides of the bowl.

Gradually mix in half of the flour mixture until just combined. Then, add lemon zest, sour cream, vegetable oil, and vanilla extract. Mix until smooth.

Fold in half of the blueberries gently. Pour the mixture into your prepared springform pan.

Sprinkle the remaining blueberries over the batter, followed by the crumble topping. Bake for 45-50 minutes.

Once baked, allow it to cool in the pan for 10-15 minutes before removal. Let it cool completely.

Prepare the lemon glaze by mixing powdered sugar and lemon juice until smooth, then drizzle over the cooled cake.