Prep: 13 minutes, Cook: 3 hours, Other: 1 hour
Slow-Cooker Size: round 6-quart
Whisk together first 4 ingredients in a large bowl; stir in milk, cream, vanilla, and butter. Add bread cubes and pecans, stirring gently just until bread is moistened. Cover and chill 1 hour.
Pour bread mixture into a lightly greased 2 1/2-quart soufflé dish; cover with aluminum foil. Pour 1 cup water into a 6-quart round slow cooker; place a wire rack to fit cooker on bottom. Set soufflé dish on rack.
Cover and cook on HIGH 3 hours or until a sharp knife comes out clean. Cool slightly before serving. Serve warm with whipped cream, if desired.
Test Kitchen Secret: To quickly make 1-inch bread cubes, stack bread slices and cut vertically into thirds; then cut crosswise into thirds.