Preheat oven to 450 degrees.
Mix ingredients for crumb topping and set aside.
In large mixing bowl mix flour, baking powder, baking soda and salt until well combined.
In seperate bowl, mix butter, eggs, sugar, vanilla and buttermilk.
Add wet ingredients to the dry. Fold to combine. Do not over mix. Just gently fold until combined.
Fold in blueberries. Mixture will be thick.
Line muffin pan with liners and fill cups all the way to the top.
Sprinkle crumble mixture on top of all the muffins.
Bake at 450 degrees for 5 minutes.
After 5 minutes, lower heat to 375 and bake for 12 to 15 minutes.
Test muffins after 12 minutes. If toothpick comes out clean they are done.
Cool on rack.
I keep mine, if they are any left haha in a big tupperware container with lid.
Hope you enjoy these. Great for snacks or breakfast:)
