Melt the 3 tablespoons of solid butter in a large skillet over high heat until foamy. Add the fruit and sauté until the pieces just begin to brown, about 5 minutes. Remove from the heat and mix in the brown sugar and vanilla.

Mix the 3 tablespoons of melted butter and the bread cubes in a medium bowl until the butter coats the bread evenly. Scatter a third of the bread over the bottom of a 3- to 4-quart slow cooker. Top with half the fruit mixture, another third of the bread, the remaining fruit, and the remaining bread. Sprinkle the cinnamon over the top. Drape a folded kitchen towel over the top and cover with the lid. Cook for 3 hours on high, or until the fruit is bubbling and brown around the edges.

Keep warm for up to 2 hours and serve warm with ice cream, if desired.