For the batter(base), first, add the dry ingredients, flour, baking powder, sugar, etc. Then, proceed with the wet ingredients such as eggs, milk, butter, and lemon zest.
Mix it all well with the hand mixer for approximately 15 minutes, and pour it in the baking pan.

Put the blue berries in a bowl and add two tablespoons of flour, and make sure to cover them in flour. That way, they don't sink to the bottom of the batter once you put them in. Set them aside for now.

Now start on the crumble topping: add in the flour, sugar, cinnamon in a bowl, and then the diced butter and start working it by hand until it becomes crumbly. Once you've achieved that step, set the topping aside.

Place the blueberries now in the batter, and once you've done that, proceed to add the crumbled topping as well.
Place that in the oven for 180°C (350 F) for 45 minutes up to 50, depending on how your batter would bake. If it's too runny still, keep it in the oven for 10 minutes more with, of course, a baking sheet covering the top of the cake.

While the cake is baking, add cream cheese, powdered sugar, and lemon juice in a bowl and whisk them together until its a runny/creamy texture and place it in the fridge while the cake is baking

After the cake has baked, leave it cool off for about 2h up to 3h.

After 2-3h, serve it with the glazing we made earlier and enjoy it. Thank you!