Make the filling: Heat oven to 450°F (232°C). In a small pot, combine apples, lime juice, brown sugar, cinnamon, nutmeg, vanilla, and salt. Cook over medium-high heat, stirring occasionally, until the apples are tender and most liquid has reduced, 15–20 minutes. Stir in cornstarch and cook 30–60 seconds to thicken. Transfer to a bowl and cool completely.

Form the rounds: On a lightly floured surface, stack the two pie crusts and roll to ¼ inch (6 mm) thick. Cut four 6-inch (15 cm) circles; re-roll scraps to cut two more.

Fill & seal: Place 1 tablespoon filling in the center of each round. Brush edges with egg wash, fold into half-moons, and crimp with a fork (or pinch) to seal well. Transfer to parchment-lined baking sheets.

Bake: Cut 2–3 small slits on top of each empanada. Brush with egg wash; sprinkle with turbinado sugar. Bake until golden, 10–12 minutes. Cool a few minutes before serving.