Cook the apples: In a skillet over medium heat, melt butter. Add chopped apples, brown sugar, cinnamon, nutmeg, and lemon juice. Cook 6–8 minutes until apples are tender but not mushy. Let cool.
Make whipped cream: In a cold bowl, whip cream, powdered sugar, and vanilla until soft peaks form.
Assemble the trifle: In a trifle bowl or glasses, layer half the pound cake cubes, half the apples, half the whipped cream, and a drizzle of caramel. Repeat layers.
Chill: Cover and refrigerate at least 2 hours, or up to overnight.