Preheat oven to 375°. Coat 18 regular-size muffin cups with nonstick cooking spray; set aside.
Prepare rice according to package directions. In medium saucepan, melt butter over medium heat; add onions, celery and bell peppers and saute 5 minutes. Remove from heat; stir in bread crumbs, Creole seasoning and shrimp. Stir in eggs. Fold in rice until all ingredients are incorporated.
Spoon mixture into muffin cups until half full; flatten tops. Bake 25 minutes. Serve warm with remoulade sauce.
Remoulade sauce: Mix all ingredients in a small bowl. If desired, substitute spicy brown or Dijon mustard for the Creole mustard. Refrigerate unused portion.
Note: To make as an appetizer, prepare as directed using mini-muffin pans; reduce baking time to 15 minutes. Use a small ice cream scoop to portion mix. Makes 48 mini cakes.