Step 1: Peel, core, and dice the apples into 1/2-inch pieces. For even cooking, try to keep the pieces roughly the same size.
Step 2: In a large skillet, melt the unsalted butter over medium heat until just bubbling.
Step 3: Add the diced apples, brown sugar, cinnamon, nutmeg, and a pinch of salt to the skillet. Toss to coat the apples evenly.
Step 4: Cook the apples, stirring occasionally, for 8-12 minutes, or until they are tender-crisp but still hold their shape. Do not overcook them to avoid a mushy texture. Remove from heat and allow the spiced apples to cool completely to room temperature.
Step 5: In a large mixing bowl, using an electric mixer, beat the softened cream cheese, granulated sugar, and vanilla extract until the mixture is smooth, creamy, and lump-free. Make sure to scrape down the sides of the bowl as needed.
Step 6: In a separate, chilled bowl, whip the cold heavy cream with an electric mixer on high speed until stiff peaks form. Be careful not to over-whip, which can turn it grainy.
Step 7: Gently fold the whipped cream into the cream cheese mixture using a spatula until just combined. Be careful not to deflate the whipped cream, ensuring the cheesecake filling remains light and airy.
Step 8: Spread approximately 1/3 of the prepared cheesecake filling evenly on the bottom of a 3-quart trifle bowl or a large, clear glass serving bowl.
Step 9: Arrange a single layer of graham cracker squares over the cheesecake filling. Break some crackers as needed to ensure good coverage across the layer.
Step 10: Spoon half of the completely cooled spiced apples over the graham cracker layer, spreading them out evenly.
Step 11: Drizzle generously with 1/3 (about 1/2 cup) of the prepared caramel sauce over the apple layer.
Step 12: Repeat the layering process: add another 1/3 of the cheesecake filling, followed by another layer of graham crackers, then the remaining spiced apples, and finally, another 1/3 (about 1/2 cup) of the caramel sauce.
Step 13: Top the trifle with the remaining cheesecake filling, spreading it smoothly and evenly to cover the top layer.
Step 14: Cover the trifle tightly with plastic wrap and refrigerate for at least 4 hours, or ideally overnight (8-12 hours). This chilling time is essential for the flavors to meld and the graham crackers to soften, creating a perfect trifle texture.
Step 15: Just before serving, drizzle the remaining 1/3 (about 1/2 cup) of caramel sauce over the top of the trifle. Optionally, garnish with extra crushed graham crackers, a sprinkle of cinnamon, or even toasted chopped nuts for added visual appeal and texture.