1. Make the dough: In the bowl of an electric mixer fitted with the paddle attachment, mix together flour, salt, and baking powder until well combined. Add butter; mix until well combined. Add yolk, milk, and sugar; mix until fully incorporated. Transfer to refrigerator and let chill for an hour.

2. Preheat oven to 375 degrees. Turn dough out onto a nonstick baking mat and roll out to a 1/8-inch thickness. Invert a 7 1/2-inch round silicone mold onto dough; using a small sharp knife, trace around the mold. Remove scraps and discard. Transfer baking mat to a baking sheet and place in oven. Bake until golden, about 15 minutes. Set aside to cool.

3. Make the apples: Increase oven temperature to 425 degrees. Place apples on a parchment-lined baking sheet and brush with melted butter. Sprinkle with sugar and transfer to oven. Bake until slightly softened, about 20 minutes.

4. Make the caramel: Place sugar in a small saucepan over low heat. Melt, without stirring, until browned, 2 to 3 minutes. Whisk in butter until smooth.

5. Reduce oven temperature to 300 degrees. Place a 7 3/4-inch round silicone mold on a baking sheet and pour in caramel. Arrange apples vertically around the perimeter of the mold, working towards the center. Transfer to oven and bake until browned and very soft, about 1 1/2 hours. Remove from oven and let cool for 1 hour.

6. Place circular piece of dough over mold and invert; serve with creme fraiche.