Happy Pi Day, my friends! Today we are making meringue topped tartlets with a brown-butter crust rather than typical pie shell. The Brown-Butter crust is first par-baked and then filled with luscious citrus custards which is topped with a heaping mound of fluffy meringue. After a few moments back in the heat we soon have a golden-brown swirls atop the perfect single-serving dessert. We use egg yolks in the curd and egg whites in the meringue. A frugal and practical solution for divided eggs, but more importantly, a tastefully balanced dessert with the bold brightness of winter citrus and the sweetness of vanilla-scented meringue.