This is so good, I don't think I'd ever get tired of it.

Press the mixture into the prepared pan with a greased spatula or wax paper, making sure it's spread evenly. Let it cool and set for about 30 minutes.
In a clean mixing bowl, beat the egg whites and cream of tartar on medium speed until soft peaks form. Gradually add the sugar, one tablespoon at a time, and continue to beat until stiff, glossy peaks form.
Spread the meringue over the cooled Rice Krispie layer, creating swirls with the back of a spoon for a decorative touch.
Optional: Use a kitchen torch to gently toast the meringue for a golden finish, or place under a broiler for 1-2 minutes, watching carefully to avoid burning.
Allow the meringue to set before cutting into squares and serving.
Variations & Tips
For those with picky eaters, you can leave out the lemon curd and zest for a more traditional Rice Krispie treat. Alternatively, try adding a teaspoon of vanilla extract to the meringue for a different flavor profile. If you're short on time, store-bought meringue can be used in place of homemade meringue. Feel free to get creative and add a handful of white chocolate chips to the Rice Krispie mixture for an extra sweet touch.