Easy Blueberry Breakfast Cake for 12

Instructions:

1. Preheat your oven to 350°F (175°C). Grease an 8x8 inch pan and line it with parchment paper, leaving an overhang for easy removal.
2. Zest your lemon and toss the fresh blueberries in a small bowl with a pinch of flour until lightly coated to prevent sinking.
3. Beat the softened butter and granulated sugar together until the mixture is pale and fluffy (about 2-3 minutes).
4. Add the egg, sour cream, vanilla extract, and lemon zest. Beat on medium speed until smooth and velvety.
5. Gently stir in the flour, baking powder, and salt using a spatula. Stop as soon as no streaks of flour remain.
6. Fold in the floured blueberries with two or three gentle turns.
7. Spread the batter evenly into the prepared pan.
8. Mix the topping sugar and cinnamon, then sprinkle it evenly across the surface of the batter.
9. Bake for 30-35 minutes until the top is mahogany-colored and a toothpick inserted into the center comes out clean or with a few moist crumbs.
10. Let the cake cool in the pan for 10 minutes.
11. Lift the cake out using the parchment handles and transfer to a wire rack to cool completely before slicing.