By hand using a fork, mix Bisquick, butter, brown sugar, cinnamon until crumbly. Add the milk and stir with a spoon until smooth. Grease an 8 x 8 x 2 baking dish. Spread batter evenly on the bottom. Pour the pieces of peaches and the juice over the top of the batter. Bake at 400 degrees for 30-35 minutes. You can eat it hot or let it cool first. Serve with vanilla ice cream.