Start at Timberline Lodge then hike up to the top of the Palmer Snowfield. Continue as if you were going to climb the Hogsback, up until about 100' below the bottom of the Hogsback. Now traverse over towards the center of the Devil's Kitchen Headwall on steepening slopes. You are aiming for the central couloir with the broad opening at its base.
Once inside the couloir, climb straight up through 2 hourglasses for 600 feet until you reach the summit ridge. Now walk over to the true summit. Keep in mind that the couloir gets as steep as 65 degrees, so prepare yourself. Descend the Hogsback.
A note on topping out: Be aware that if you gain the ridge up through one of the Devil's chutes too far to the right, you will have some towers to skirt and some steep 45-50 degree slopes to traverse and knife-edge ridge to cover with a bad runout before you can just "walk over to the summit." The right-most chute above a large debri fan in Devil's Kitchen is probably the easiest to gain the ridge from, but it sets you up for some more perks, per above.
Conditions are very important for this climb. You want it to be dense packed powder or ice on the route. Extreme wind gusts are quite common at the hourglasses where the wind is funneled down right in your face. Expect gusts 20 - 30 miles per hour higher than on the Hogsback.
Crampons, 2 Ice Tools, Rope, Harness, Pickets, Ice Screws, Helmet, and a belay device to rapel if snow conditions are bad.