Boil squash and carrot together until the carrot is tender. Allow both to cool. Slide skin off carrot. Being careful with squash, remove its seeds and peel. Blend carrots and squash together. Don't over-blend: preserve some texture. Add cinnamon sugar and salt to taste.
Add frothy eggs to carrot/squash mixture. Grease an 8-inch loaf pan. Coat the grease with oatmeal. Mix about 1/2 cup oatmeal into casserole. Gently fold in green peas, then put mixture in casserole pan. Sprinkle remaining oatmeal on top and dot with butter. Bake at 350 degrees F. 30 to 40 minutes until brown on top. Once cooked, it can be served immediately or frozen for later consumption.
* Cinnamon sugar is a mixture of sugar and powdered cinnamon. Commercial cinnamon sugar mixtures are mostly sugar. My mom prepares her own mixture with the emphasis decidedly on the cinnamon.