Mix Bisquick, sugar, milk and vanilla. Pour melted butter into a 9 x 13 pan then pour the batter over the butter. Sprinkle the turbinado sugar over the batter
Bake in a 350 degree oven for about 1 hour until no longer jiggly and a toothpick comes out clean and golden brown on top. Serve warm or cold and it’s even better with ice cream!