Just open: Black Star Pastry, Powerhouse Museum

Museum-goers will now be able to treat themselves to Black Star Pastry's signature strawberry watermelon cake with the arrival of a new spin-off from the cult Newtown bakery at the Powerhouse Museum in Ultimo.

The new venue, which opened quietly in December, will be the third for owner Christopher Thé, who opened his original Newtown shop in 2008, followed by an outlet in Rosebery a year ago.

The Powerhouse venture takes over two pre-existing sites within the museum complex – a modern 100-seat cafe on level three and a smaller beach-themed kiosk on level one that opens onto the playground.

The latter has been revamped with an expanded play area and requires museum admission. The cafe has free entry.

Thé hopes the new venture will be a key part of the reinvigoration of the museum and its surrounds, including the redevelopment at Darling Harbour and the forthcoming goods line.

Former Garfish and Cottage Point Inn chef Matteo Margiotta heads up the kitchen, serving up an all-day menu featuring family-friendly items alongside signature Black Star treats such as the strawberry watermelon cake and lamb shank pie.

"There's everything we always do and it's accessible and affordable," Thé says.

"We really focus on flavour and just simple good cooking. That kind of philosophy [is just] going into something that's a little bit bigger than what we [normally] do."

While the new venture will serve "take and go" baked favourites such as quiches and pies, customers can also linger for light sit-down meals.

Breakfast options range from avocado on toast to roasted mushrooms with almond pesto, ricotta, rocket and truffle oil. Thé is betting on the wagyu brisket burger to be the pick of the lunch options.

Children's meals include a healthy bento box and spaghetti with meatballs.

"If you think about museums and galleries, often there's not a lot of thought put into food and so we're trying to up the game and offer something that's of high quality," Thé says.

Coffee is by Little Marionette and wine and beer will be introduced in coming weeks. A rooftop bar area is also on the horizon and Thé plans to create an "elite kitchen" area upstairs which will provide staff with much-needed space to experiment with new recipes.

Black Star Pastry, 500 Harris Street, Ultimo, 7.30am-4.30pm weekdays, 9am-4.30pm weekends