Combine first 6 ingredients in a large bowl; beat at medium speed with an electric mixer until smooth. Add cream; stir well. Pour into a lightly greased 3- or 4-quart oval-shaped slow cooker.
Combine pecans and remaining 3 ingredients in a small bowl. Sprinkle over sweet potatoes. Cover and cook on HIGH 3 to 4 hours or until sugar melts on top of casserole.