1. Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish to ensure easy serving later.
2. In a large skillet, melt the butter over medium heat. Add the brown sugar, cinnamon, nutmeg, and sliced apples. Stir to coat the apples evenly and cook for about 8-10 minutes, until the apples are soft but still hold their shape. Remove from heat and stir in the vanilla extract. Set aside to cool slightly.
3. While the apples are cooling, separate the cinnamon roll dough into individual rolls. Flatten each roll gently with your fingers or a rolling pin to create thin discs approximately 4-5 inches in diameter. This helps create thinner layers that bake evenly.
4. Place a layer of flattened cinnamon rolls on the bottom of your prepared baking dish, slightly overlapping to cover the entire surface.
5. Spread half of the cooked apple mixture evenly over the cinnamon roll layer. Sprinkle half of the chopped nuts over the apples if using.
6. Repeat the layering process: add another layer of flattened cinnamon rolls, then the remaining apple mixture, and nuts.
7. Finish with a final layer of cinnamon roll discs on top.
8. Cover the dish loosely with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the top is golden brown and the cinnamon rolls are cooked through.
9. While the lasagna bakes, beat the softened cream cheese with powdered sugar and lemon zest (if using) until smooth and creamy.
10. Once the Apple Cinnamon Roll Lasagna has cooled for about 10 minutes, drizzle or spread the cream cheese frosting over the top. Serve warm for the best gooey, melty experience.

A quick tip from my own kitchen: don’t skip flattening the cinnamon rolls. It makes the layering more even and helps the lasagna bake through without any doughy surprises. Also, I find letting it cool slightly before frosting keeps everything intact and less messy—though the kids often prefer it straight out of the oven!