In a large mixing bowl, combine the mashed potatoes, eggs, flour, garlic powder and onion powder.
Mash well to combine.If you feel like the mixture is too thick to manage properly, you can add a small amount (1 tbsp. at a time) of either water or milk until you reach a manageable consistency. But the "batter" should be a little on the thicker side.
Oil your pan.
Spread the potato mixture out in a pan or, if you're like me, the pancake plates of your waffle maker.
Cook until browned, flip, and cook until the other side is browned. Each side should be about 7-8 minutes if you make this exactly as the recipe states. If you thin them out, they should only take about 5 minutes on each side, but you'll want to make very sure (in either case!) that the egg gets fully cooked. These don't burn all that easily, so feel free to cook a little longer if you are unsure. Just keep an eye on them.
Please note that the nutrition data below is a ballpark figure. Exact data is not possible. Data does not include cooking oil.