Preheat your oven to 375°F (190°C).
Peel and chop the potatoes, then place them in a large pot of cold, salted water.
Bring the pot to a boil and cook until the potatoes are fork-tender, about 15-20 minutes.
Drain the potatoes and return them to the pot, then add in butter, milk, garlic powder, salt, and pepper.
Mash the potatoes until smooth and creamy, adjusting milk as needed for consistency.
While the potatoes cool slightly, prepare the chicken by coating it in olive oil, then dredging it in the breadcrumb mixture and Parmesan.
Heat a skillet over medium heat and cook the chicken for about 6-7 minutes on each side until golden and cooked through.
In a baking dish, layer the creamy mashed potatoes, followed by the crispy chicken on top.
Sprinkle any remaining breadcrumbs and Parmesan cheese over the top.
Bake in the preheated oven for about 25-30 minutes, until heated through and the top is golden brown.
Let it rest for a few minutes before serving to allow the layers to set.