For the salted honey crumble: In the bowl of an electric mixer fitted with the paddle attachment, combine the brown sugar, butter, clover honey and vanilla; beat on medium-high speed until light and fluffy, about 2 minutes. Add the flour and salt. Mix on low speed just until the mixture comes together and develops a sandy texture. Refrigerate in an airtight container for at least 30 minutes.
For the muffins: Preheat oven to 350 degrees. Butter 12 muffin cups and dust with flour. In a small bowl combine the flour, baking powder and salt.
In the bowl of an electric mixer fitted with the paddle attachment, cream together sugar, butter, honey and vanilla. Add eggs one at a time and mix well; stir in milk. Add the dry ingredients and mix just until combined. Remove the bowl from the mixer and gently fold in blueberries using a rubber spatula. Scoop the mixture into the prepared muffin cups, filling them about three-fourths full.
Sprinkle each top with 1 tablespoon of the salted honey crumble. Bake on the center rack of oven until golden, about 30 to 35 minutes.