Preheat oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil.

Lay bacon on the prepared baking sheet. Mix pecans, brown sugar, chili powder, and sea salt together in a bowl. Sprinkle evenly over the bacon.

Bake in the preheated oven until crisp, and browned, 18 to 20 minutes. Transfer to a rack to cool. Chop bacon into rough pieces.

Melt butter in a nonstick skillet over medium-high heat. Add apples and 1 tablespoon maple syrup. Saute, stirring only every 60 to 90 seconds, until apples are tender and brown, about 8 minutes. Mix in remaining 2 tablespoons maple syrup and cinnamon. Transfer to a bowl.

Cut a round of parchment paper slightly larger than the round of Brie cheese. Place the Brie cheese on the parchment paper; place onto a baking sheet. Top with the cooked apples to make a big mound.

Bake in the hot oven for 5 minutes. Add bacon-praline mixture on top of the Brie. Continue baking until top is bubbly, 2 to 3 minutes more. Transfer to a serving platter using a large spatula. Sprinkle with sea salt and rosemary.