Short of buying a new fork with a longer steerer column you have two choices.

The first is a stem with more rise angle. If you choose to go this route, select the length carefully because, besides raising the handlebar, it's also moving it closer to the saddle.

The second is a device similar to the Zoom HeadsUp. It clamps onto your fork's steerer in place of your stem and allows you to reinstall your existing stem 23mm (almost an inch) higher.