Break each graham cracker square into 4 pieces and cut banana into small chunks. Put them into a medium serving bowl or divide among 4 small serving dishes. Combine the brown sugar and cornstarch in a medium saucepan. Stir in the soymilk and caramel topping. Cook, stirring over moderate heat until pudding just comes to a boil and thickens. Remove from heat and stir in vanilla. Pour the pudding over the graham crackers and bananas and stir well. Cover and refrigerate. Serve pudding well chilled. Makes 4 servings.