Add all ingredients to a medium bowl. Mix with a fork or your fingers until you have a crumbly, small lumpy dough. Reserve in the refrigerator until needed.
For the cupcakes:
Preheat oven to 374º F (190° C). Place cupcake liners in a 12 muffin pan. In a medium bowl, sift together the flour with the baking powder, baking soda and salt.
In a different large bowl, add the cream cheese with the butter and sugar. Beat using a hand whisk or electric mixer for 2 minutes until light and fluffy.
Add the eggs one at a time, beating for 30 seconds after each addition. Add the lemon juice, lemon zest and vanilla extract and beat until well blended. Add in the milk and beat for 1 minute more until very smooth.
Add the flour mixture in two additions, beating for 20 seconds after each addition to obtain a smooth, soft batter. Mix in the blueberries doing folding motions just until incorporated, so they don't fall apart too much.
Carefully pour the mixture into the 12 muffin cups, filling each one 3/4 of their capacity. Top each muffin with a little of the crumble that was prepared. before.
Bake the muffins at 374º F (190° C) for approximately 16 minutes or until they are lightly browned and a wooden toothpick comes out clean when inserted.
Remove the muffins from the oven and let them cool down for at least 10 minutes and then decorate them with glaze.
For the lemon glaze:
Add all ingredients to a small bowl and mix with a fork until a smooth glaze forms. Using the same fork, decorate each muffin with a little of this glaze by drizzling on top.