Feb 15 (Reuters) - Shares of Shake Shack soared more than 21% on Thursday after the restaurant chain topped quarterly earnings expectations, on the back of higher prices and strong demand for its gourmet burgers and fries.

Its shares were trading at $91.19 premarket. The stock has gained about 33% over the past 12 months.

The company also saw traffic growth through the fourth quarter, defying an industry-wide slowdown in visits that has hurt major fast-food players, including McDonald's.

Shake Shack has been rolling out new initiatives, including self-service ordering kiosks, to speed up service and improve customer experience at its restaurants, while limited-time menu launches have also drawn a bigger crowd.

The company reported total revenue of $286.2 million for the quarter ended Dec. 27, up 20% from a year earlier and above Wall Street estimates of $280.3 million, according to LSEG data.

Its adjusted earnings of 2 cents per share was above estimates of 1 cent. (Reporting by Deborah Sophia in Bengaluru; Editing by Krishna Chandra Eluri)