Preheat your oven to 350°F or 175°C (350°F).
Peel the potatoes and chop them into uniform 1-inch chunks.
Place them in a pot of generously salted water, bring to a boil, and cook for 8-10 minutes until they are just tender enough to be pierced with a fork but still firm.
Drain the potatoes completely and gently prick each chunk a few times with a fork to help the marinade absorb.
In a large bowl, whisk together the yogurt, turmeric, garam masala, salt, cumin, and black pepper to form a smooth, thick paste.
Add the hot, drained potatoes to the bowl and gently toss until every piece is generously and evenly coated in the vibrant spice mixture.
In a medium, oven-safe casserole dish or skillet, melt the butter over low heat.
Add the bay leaves and crushed red pepper, stirring for about a minute until fragrant.
Sprinkle in the sugar and continue to stir until it dissolves and just begins to turn a light golden brown.
Immediately add the yogurt-coated potatoes to the casserole dish. Gently stir and toss to coat them in the fragrant, caramelized butter.
Cover the dish tightly with a lid or foil.
Bake in the preheated oven for 30 minutes, or until the potatoes are fully tender and the sauce has thickened.
Serve hot, garnished with fresh cilantro if desired.
