1. In a large bowl, beat eggs and oil. Combine the flour, sugar, baking powder, salt and cinnamon; add to egg mixture and mix well. Stir in zucchini. Spread into a greased 15-in. x 10-in. x 1-in. baking pan.
2. Bake at 350° for 20-25 minutes or until a toothpick inserted near the center comes out clean. Cool completely on a wire rack.
3. In a small bowl, beat the cream cheese, butter and vanilla until smooth. Gradually beat in confectioners' sugar. Add enough milk to achieve spreading consistency. Frost cake and cut into squares. Store leftovers in the refrigerator. Yield: about 24 servings.