Sweet apple butter, creamy brie, caramelized onions, and savory pancetta all layered on buttery puff pastry. This tart is an elegant yet simple appetizer perfect for fall entertaining.
Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper. Keep puff pastry cold until ready to use.
Melt butter in a skillet over medium heat. Add onions with a pinch of salt. Cook slowly for 25–30 minutes, stirring often, until deep golden and caramelized. Remove and set aside.
In the same skillet, cook pancetta for 5–7 minutes until crisp. Drain on paper towels.
Roll puff pastry into a 10x14-inch (25x35 cm) rectangle on a floured surface. Transfer to the prepared baking sheet. Score a 1-inch (2.5 cm) border around the edges without cutting all the way through.
Spread apple butter evenly across the pastry inside the border.
Layer apples and brie alternately over the apple butter, slightly overlapping slices.
Sprinkle caramelized onions and pancetta evenly over the top. Scatter thyme leaves and a pinch of flaky salt.
Fold pastry edges slightly over the filling, pinching corners to seal. Brush edges with beaten egg.
Bake 25–30 minutes, rotating halfway, until puffed and golden brown.
Let cool 5 minutes before slicing into portions. Serve warm.
Keyword Appetizer, Apple, Apple Butter, Appy Hour, Brie, Cheese, Drinks & Apps, Fall Flavors, Fall Series, Food, Friendsgiving, Pancetta, Puff Pastry, Recipe, Recipes, Savory, Tart, Thanksgiving