Mix 1/3 cup mayo and next 5 ingredients in medium bowl. Stir in 2 tsp. zest and fish. (
Mixture will be moist.)
Mix lemon juice, garlic, dill, and remaining mayo and lemon zest until blended. Refrigerate until ready to serve.
Combine bread crumbs and butter in separate bowl.
Add 1 Tbsp. fish mixture; turn to evenly coat. Shape into ball; place on baking sheet sprayed with cooking spray. Repeat with remaining fish mixture, placing balls 1 inch apart on baking sheet; flatten with spatula to 1/4-inch thickness.
Bake 10 min. on each side or until fish cakes are golden brown on both sides.