One way to conjure up the past is with sugar, cream and fizz. This is exactly what the new Jazz City Milk Bar in Darlinghurst does – it evokes the type of old-school American diner where you sip on shakes or root beer floats and then battle spoons over who gets to finish the banana split.

Retro-style signage adds to the time-tripping feel, as does the black-and-white footage screening on one wall (I caught a glimpse of an old Miles Davis concert), as well as the checkered flooring, Deco lights and other flashback-rich touches.

Of course, there are some contemporary influences, as the scrolling LED sign in the open kitchen reminds us. This spin-off to Dan McGuirt’s nearby Jazz City Diner is inspired by “Albert Adria, Christina Tosi, Karen McGuirt and Mr Lou”. So you know that this is a place ruled by invention and fun.

Here, you can chase away the heat with the fizz and pop of a Coke Spider ($8) or A&W Root Bear Float; or a malted milkshake ($8) in a run of flavours (raspberry, peanut butter, coconut, mango, strawberry – passionfruit is especially delicious).

Currently, the menu is only serving cakes and sweets, so you can try a Peanut Butter and Jelly Cookie ($4), Banana Split ($9) or a Coconut Cream Pie ($8) – the latter’s whipped-soft, coconut-toasted topping is nicely paired with a splodge of strawberry ice-cream or whatever scoop takes your fancy. You can also pick up some Bazooka Joe gum or Tootsie Rolls, if you need an extra sugar fix.

Expect more comprehensive – and savoury – menus later in the week, with weekend breakfast likely to start this Sunday. Eggs Louis Armstrong, Oatmeal-Mushroom Risotto and ‘Killer Diller’ Cajun Meatloaf with Buttermilk-mashed Potatoes are what’s on the cards, according to Good Food.

So it’s not just about a sweet-charged past; at Jazz City Milk Bar, the future looks good, too.

Jazz City Milk Bar, Republic 2 Courtyard, Palmer Street (between Burton and Liverpool Streets), Darlinghurst NSW. Follow on Facebook