Put the blueberries in a large but shallow baking dish. You can vary the amount of blueberries by half a cup either way without making any difference; 6 1/2 cups is what I happened to have on hand. Lightly sprinkle a few pinches of flour over the blueberries to help absorb the berry juice. You can omit the flour if you want; if you do, there will be more leftover berry juice in the bottom of the pan. Sprinkle the lemon peel over the berries. The tartness of fresh lemon peel balances the sweetness of the berries and topping, so use the amount that suits your personal taste. Then go change the name of the recipe and put your own name in; you've customized it, you deserve it! :) Reduce the amount of lemon peel if you decide to cut back on the amount of topping. Mix together the remaining ingredients; it will be easier if the butter and brown sugar are nice and soft. Sprinkle the mix on the berries. Bake for 25 minutes at 275-degrees F.