2 cups/199g and 1-2/6-12g Tbsp of sifted, all purpose flour separated
2 teaspoons baking powder
1/2 teaspoons salt
1/4 cup/57g (1/2 stick) unsalted butter, softened
3/4 cup/144g sugar
1 large egg
1/2 cup/125ml milk
1 pint/450gblueberries
Topping ingredients:
1/4 cup/57g unsalted butter, softened
1/2 cup/96g sugar
1/3 cup/33g sifted all purpose flour
1/2 teaspoon cinnamon

Preheat the oven to 375F/190C/Gas 5 Grease an 8 inch/20cm spring form pan

Sift together the 2 cups/199g of flour, the baking powder and the salt. Set aside. Cream the butter and sugar until fluffy, about 3 minutes. Beat in the egg. Add the flour mixture in 3 parts, alternating with the milk. Toss the berries with the remaining flour (to separate and scatter evenly throughout the batter) and fold in. Pour batter into the prepared pan. Set aside. Combine ingredients for topping with a fork to make crumbly mixture. Sprinkle this over the batter.

Bake for one hour. Test for doneness by gently inserting a fork. If it does not come out clean, give the cake another 5 to 10 minutes to bake. When the cake has cooled, run a knife around the edges and lift the cake out of the pan.