1-First Step: Preheat your oven to 400°F (200°C). Grease a 12-cup muffin tin generously with cooking spray or brush with a bit of melted butter. This prevents sticking and ensures your parmesan potato stacks pop out easily with crispy bottoms. Gather all ingredients to streamline assembly this mise en place keeps busy schedules on track.

2-Second Step: Wash and dry 4-5 medium Yukon Gold potatoes. Use a mandoline slicer set to 1/16 inch thick for uniform potato slices. Aim for even thinness to promote crispiness; thicker slices lead to undercooked centers. If no mandoline, a sharp knife works but takes longer. This yields about 12 stacks, perfect potato side dish portions.

3-Third Step: In a small bowl, mix 1/2 cup melted butter, 1/2 cup grated Parmesan, 2 minced garlic cloves, 1 tsp thyme, salt, and pepper. Stir until smooth. This butter-Parmesan blend coats each layer for maximum cheesy flavor in your oven baked parmesan potato stacks.

4-Fourth Step: Stack 4-5 potato slices per muffin cup. Brush the bottom with the mixture, add a slice, brush again, and repeat. Top each stack with extra Parmesan and a thyme sprinkle. Gently press down for compact shape this helps them hold together during baking. For dietary tweaks, layer in vegan swaps here seamlessly.

5-Fifth Step: Bake on the middle rack for 45-55 minutes. Watch for golden tops and crispy edges; rotate the tin halfway for even browning. Internal temp should hit 190°F for tender potato stacks. If edges brown too fast, tent with foil. This step creates the signature crunch of crispy parmesan potato stacks.

6-Sixth Step: Cool in the tin for 5-10 minutes. They firm up for easy removal. Run a knife around edges if needed, then transfer to a platter. Garnish with fresh thyme or parsley for pop. Total time: 1 hour, serving 6 as a potato side dish.