Heat oven to 350º. Gently fit 1 wonton wrapper into each of 36 small muffin cups, 1 3/4x1 inch. Bake 8 to 10 minutes or until light golden brown. Remove from pan; cool on wire racks.
Mix remaining ingredients except sour cream in medium bowl. Just before serving, spoon bean mixture into wonton cups. Top each with 1/2 teaspoon sour cream.