Blueberry crumble muffins

(a slight variation on my mom's recipe)

Muffin ingredients
1/2 cup salted butter
1/2 cup sugar
1 large egg
2 cups flour
1/2 tsp baking powder
1/2 tsp baking soda
1/4 tsp salt
1/2 tsp. cinnamon
1/2 cup milk
1/2 cup crème fraîche
1 tsp vanilla extract
1 1/2 cup wild blueberries

Topping ingredients
1/2 cup flour
1/2 cup rolled oats
1/3 cup brown sugar
1/2 tsp cinnamon
1/8 tsp salt
6 Tbsp salted butter

Cream butter and sugar until fluffy then add egg. In a separate bowl combine dry ingredients. In a second bowl combine milk, crème fraîche and vanilla.

In yet another bowl, combine all the dry topping ingredients and then with a pastry cutter, cut in the butter.

Combine flour and milk mixture alternately into the creamed butter. Fold in blueberries. Do not over stir. Finish with topping. Pour mixture into forms.

Bake at 200°C (400°F) for 30 minutes.