Preheat oven to 350°. In a large bowl, whisk together first 9 ingredients and, if desired, rum. Gently stir in bread; let stand 15 minutes or until bread is softened.
Transfer to a greased 8-in. square baking dish. Sprinkle with almonds.
Bake, uncovered, until puffed, golden and a knife inserted in the center comes out clean, 35-40 minutes. Serve warm, with ice cream.
