Grease a 9x13" baking dish. Arrange the bread in two layers, with six slices of bread on each layer.In a large bowl, mix together eggs, sugar, vanilla, cinnamon, and milk. Whisk until blended (but not too bubbly).Pour the mixture over the french toast, making sure to cover them evenly, as well as in between the slices as well.Cover with foil and refrigerate for 8 hours (or overnight).When ready to bake, preheat oven to 350 degrees.Remove from refrigerator and sprinkle with raspberries.In a small bowl, combine butter, flour, and brown sugar until completely incorporated. Drop in teaspoonfuls over the french toast.Bake 35-40 minutes, until slightly puffy and golden.