01 -
Preheat oven to 180°C (350°F). Grease and flour a 13x9-inch baking pan. In a medium bowl, combine flour, baking powder, and salt. Set aside.
02 -
Cream softened butter and granulated sugar in a large bowl until light and fluffy. Add the egg and vanilla extract, and mix until fully combined.
03 -
Gradually add the dry mixture to the wet ingredients, alternating with milk, beginning and ending with the flour mixture. Mix until smooth. Fold in the blueberries and pour batter evenly into the prepared pan.
04 -
In a small bowl, combine granulated sugar, flour, and cinnamon. Cut in the chilled butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
05 -
Sprinkle the crumb mixture evenly over the batter in the pan.
06 -
Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean. Allow to cool completely in the pan on a wire rack.
07 -
In a small bowl, whisk powdered sugar, lemon juice, and lemon zest until a smooth glaze forms.
08 -
Drizzle the lemon glaze over the cooled cake, letting it seep into the top. Slice and serve.