Preheat the oven to 350°F (175°C). Grease and flour a 9-inch baking pan.
Combine flour, baking powder, baking soda, and salt in a bowl. Set aside.
Beat butter and sugar until light and fluffy. Add eggs one at a time. Mix in lemon zest, juice, and vanilla.
Gradually add the dry ingredients, alternating with sour cream. Gently fold in fresh blueberries.
Spread batter evenly in the prepared pan.
Mix crumb topping ingredients, cutting in cold butter until crumbly. Sprinkle over the batter.
Bake for 40 minutes or until a toothpick comes out clean. Let the cake cool.
For the glaze, whisk powdered sugar, lemon juice, and zest until smooth. Drizzle over cooled cake.