Cut gluten free bread into cubes at least 3/4-1 inch in size. If using frozen, already cubed bread, measure out 6 cups of bread cubes and allow to sit out at room temperature while you prepare the other ingredients.
Preheat oven to 350℉.
In a mixing bowl, whisk together the eggs or egg substitute, gluten free beer, coconut milk and cinnamon.
Arrange 4 cups of bread cubes in pan and cut butter into small pieces, distributing across the top.
Spread half of the berries on top, then sprinkle with 2 tablespoons of brown sugar. Pour half of the liquid mixture over top of the bread cubes.
Arrange the remaining bread cubes on top, pressing down into the other layers. Sprinkle the remaining berries and brown sugar, then pour on the remaining liquid. Press down on top of the bread cubes again to submerge all the bread into the liquid.
Bake for 15 minutes, then cover loosely with foil and reduce the oven temperature to 300℉ and bake another 15 minutes. Remove foil and bake until the tops are lightly browned and the liquid is fully absorbed.
Remove to cool slightly before serving.