Preheat the oven to 425.
In the bowl of a stand mixer, cream the butter and sugar for 5 minutes until light and fluffy.
Add the eggs, one at a time, make sure they are well mixed in after each one.
Add the vanilla.
In a separate bowl combine the flour, salt, baking powder and lemon zest.
To the creamed mixture alternate adding the dry ingredients and milk, do not over mix.
Don't wait until the batter is completely combined, add the blueberries while it still looks messy. Fold in to the batter until just combined.
Line a 12 cup muffin tin with liners, evenly disperse the batter into each liner and top with the crumb.
Bake for 5 minutes at 425 and then turn the heat down to 375 and continue baking for 20 minutes.
Check by inserting a toothpick in the center.
If it comes out clean they are done.
Cool until they aren't too hot to handle and then transfer the blueberry muffins to a wire rack.