Use fresh key limes when possible for the brightest flavor; Persian limes may be substituted but have a different flavor profile., Allow the crust to cool completely before adding the filling to maintain crispness and distinct layers., Cool the baked bars fully before cutting to ensure clean portions and proper filling texture., Variations include toppings like chocolate ganache, toasted coconut flakes, candied lime peel, macadamia nut crumble, blood orange zest, passion fruit swirl, or seasonal fruits., For gluten-free variation, use gluten-free graham crackers such as Pamela’s., Bars can be stored in the refrigerator for 3–5 days in an airtight container or frozen individually for up to 3 months., Thaw frozen bars at room temperature for 30–45 minutes before serving; add garnish like whipped cream or lime zest if desired.