Northern Blueberry Pie

I love this dessert. Don't even bother making a blueberry pie unless you have Northern Ontario blueberries.
This is from a Betty Crocker cookbook I was given when we were first married. I pass this off as my secret family recipe. (Oops, until now).
I use a ready made pie shell because I am hopeless with pie crusts. If you're not, make it from scratch.

1/3 cup sugar
1/4 cup flour
1/2 tsp. cinnamon
3 cups fresh blueberries
1 tsp. lemon juice

Heat oven to 425. Mix sugar, flour and cinnamon. Stir in blueberries. Turn into pie plate. Sprinkle with lemon juice. Top with crumble topping below. Cover edge of pie with aluminum foil to prevent excessive browning; remove foil during last 15 minutes of baking. Bake until juice begins to bubble through, 35-45 minutes. Top with ice cream. Prepare for a barrage of compliments.

Crumble Topping

1 cup flour
1/4 cup sugar
cut in 1/4 cup hard butter with pastry blender
I'm never exact with these amounts, I go by the consistency of the crumble.