How to Make It
Grease a 6-quart slow cooker with 1 tablespoon butter. Arrange bread slices in bottom of slow cooker. Whisk together ¾ cup sugar, 3 teaspoons cinnamon, and nutmeg. Whisk in eggs, half-and-half, and vanilla. Pour over bread. Cover and chill at least 8 hours or up to 18 hours.
Whisk together remaining ¾ cup sugar, 1 teaspoon cinnamon, and flour in a bowl. Cut in remaining 4 tablespoons butter until crumbly; stir in pecans. Cover and chill until ready to use.
Remove bread mixture from refrigerator. Sprinkle pecan mixture over bread mixture. Cover and cook on HIGH 1 hour. Reduce heat to LOW; cover and cook 3 ½ hours or until puffed and set.