YouTube personality Hannah Hart is engaged to longtime girlfriend Ella Mielniczenko.

Hart told PEOPLE that she asked Mielniczenko to marry her while the couple vacationed in Hawaii, where Hart first declared her love to her future bride.

“When I think of the epitome of our relationship, it's sitting on the beach at night without judgment,” Hart said of her decision to organize a beach proposal.

Hart hid Mielniczenko's engagement ring in a sand castle bucket and proposed at sunset.

“I thought she was pranking me, because we fake propose to each other in bad situations – like at the line at IKEA on a Saturday – until she pulled out the box,” said Mielniczenko, an executive producer at Buzzfeed.

Hart, 31, found fame cooking while intoxicated on her YouTube series My Drunk Kitchen, which is as entertaining as it is informative. She is also the author of My Drunk Kitchen: A Guide to Eating, Drinking and Going With Your Gut, a parody self-help book which became a New York Times bestseller. A six-episode reality series titled I Hart Food premiered last year on Food Network. The show featured Hart dining in various cities.

(Related: Hannah Hart gets show on Ellen DeGeneres' digital network.)

The couple plans to marry in 2020.