1 (17.5 ounce) package frozen puff pastry, thawed
6 red apples, thinly sliced
½ cup lemonade
12 pats unsalted butter
½ cup superfine sugar
½ cup apricot preserves
1 pinch coarse sugar crystals, or as needed
Preheat oven to 350 degrees F (175 degrees C).
Cut puff pastry into 12 equally-sized squares and arrange on a baking sheet.
Dip apple slices in lemonade and place diagonally onto each puff pastry square; top each with 1 pat butter. Sprinkle superfine sugar over each square.
Bake in the preheated oven until tartlet edges are golden, about 12 minutes.
Bring apricot jam to boil a saucepan; cook and stir until jam is thinned, 1 to 2 minutes. Brush jam onto warm tartlets; sprinkle each with sugar crystals.
