Heladería Gruta is an old school ice cream parlor in Belgrano that has seemingly (and thankfully) not changed its decor since it opened in 1965. The retro, neon green walls and original menu are perfection.
Get any classic flavor like dulce de leche or sambayon to enjoy it like a local, and don't miss their famous candied almonds (almendras garrapiñadas). They make them in-house by caramelizing the almonds with sugar to form a glossy, crisp shell. If you order a quarter, half, or full kilo they will put almonds on top of your ice cream to bring home.