Preheat oven to 350F (180C)
Line your muffin pan with muffin cups
In a large bowl, add flour, baking powder, salt and sugar. Mix well.
Grate or cut in the butter until crumbly.
Add milk, vanilla, sourdough discard, and egg. Combine until moist.
Add in the strawberries and mix just until combined.
Scoop about 1/4 cup of batter into each cup
In a separate mixing bowl, make the crumb topping by cutting together the flour, sugar and butter until crumbly.
Sprinkle on top of each muffin cup.
Bake in a preheated oven for 25mins.