Preheat oven to 375º. Line muffin tins with paper liners.
Wash and dice the fresh strawberries.
In a small bowl, gently toss the strawberries in a quarter cup of flour to coat evenly.
Cream the butter and sugars together in a bowl. Beat in the egg and vanilla.
In a separate bowl, combine the flour, salt and baking powder. Mix well.
Gradually add the buttermilk and flour to the butter mixture, alternating between flour and buttermilk. Mix until combined.
Gently fold in the strawberries.
Add about 1/4 cup of the dough to each muffin cup.
Prepare crumble topping using an electric mixer. Mix together the sugars, flour and cold butter until it forms a crumb.
Add the crumb topping evenly to the top of each muffin.
Reduce the oven heat to 350º and bake the muffins for 20 minutes, or until the tops begin to brown.
Allow to cool on a wire rack.
Enjoy while nice and warm or store for up to 2 days.
