A dark, heavy chocolate cake has little appeal on a hot, humid August day. Perhaps that's why my sister, Lisa, who favors chocolate over most things, opts for ice cream pie instead of cake for her summer birthday celebration. Unlike a bowl of ice cream, which can't hold many candles, the expanse of this pie gives ample opportunity for ceremonious lighting. True to its name, Black-Bottom Pie has a tasty, dark-colored chocolate crust. A satisfyingly thick, fudgy sauce covers the crust before the ice cream is generously added. Mint chocolate chip is Lisa's preferred flavor, but almost any ice cream will work with this recipe: coffee, strawberry, dulce de leche, or even plain vanilla. Summer birthdays scream for ice cream, but so does any sticky, sweltering day.