SEATTLE — Food is becoming more popular among Starbucks Corp.’s customers. It wasn’t that long ago that one in five customers were attaching food to their orders, said Brady Brewer, chief marketing officer. Today, two in five are adding food and the company wants to entice more orders with craveable menu additions. A key focus is menu options that may be eaten with one hand.

“That's what we've called it — one-handed meals — because often they (customers) have a phone in the other hand or maybe a steering wheel,” Mr. Brewer said during Starbucks’ investor day that was held Sept. 13. “Breakfast sandwiches have been incredible for us, with a success at 19% year-over-year growth.”

He added that Starbucks is on track to sell over 300 million breakfast sandwiches and 100 million egg bites from its US company-operated stores this year.

“But we're still in the early days of food, whether in the US or around the world,” Mr. Brewer said.

New menu options being considered include pastries baked fresh daily, portable salads, more plant-based items and egg-based items.

“We'll continue to innovate on food — fresher, healthier, innovative, thoughtfully crafted food — and food will continue to drive our ticket as a craveable complement to our beverages,” Mr. Brewer said.

But adding more menu items in conjunction with consumer demand for more customized and premium beverages, creates in-store problems that slows production.

Under the leadership of Howard Schultz, interim chief executive officer, Starbucks is reinventing many facets of its business in order to improve customer experience. One area of focus is food and beverage production.

“By unlocking beverage and food production, we will significantly reduce the complexity for our partners,” said John W. Culver, group president of North America and chief operating officer. “Customer demand for cold beverages is expected to continue outpacing hot beverage growth in the coming years. Cold beverages are increasingly more complex; they are more time consuming and the surge in volume has caused bottlenecks in our stores.”

Starbucks has implemented what it calls its Siren System to simplify tasks across both its beverage and food platforms. With the system, the time it takes to make a mocha Frappuccino is reduced from 83 seconds to 35 seconds, according to the company, and the time to warm a breakfast sandwich or egg bite also is reduced. A key to speeding the food warming process is the food is warmed and served in the same packaging.

“It's a huge unlock for our customers, and it's a big win in helping us become more effective and more efficient at doing our jobs to serve our customers every day,” Mr. Culver said.