EAST LANSING, Mich. -- Jack Allen never thought he would get his number called on Michigan State's Senior Day.

The game became so lopsided that the fifth-year senior center found himself in the backfield, rather than snapping the ball, following a Penn State turnover during the fourth quarter.

Allen used a stiff arm and rumbled into the end zone, capping a 55-16 romp on Saturday at Spartan Stadium that advanced the No. 5 Spartans into the Big Ten championship game.

"It was in (the playbook) for about five minutes," Allen said of his six-yard score.

The player he was snapping the ball to most of the game, fellow senior Connor Cook, returned from a one-game absence to throw three touchdowns.

The Spartans (11-1, 7-1 in the Big Ten), who upset Ohio State 17-14 a week earlier and won the East Division's head-to-head tiebreaker, will face No. 4 Iowa in Indianapolis on Saturday night.

The victor will almost assuredly be selected for the College Football Playoff.

"The way it looks right now, I would think the winner of this football game goes to the college playoffs," Michigan State head coach Mark Dantonio said.

"An 11-1 team that was No. 5 last week and the No. 4 team, playing an extra game. So, there's added risk to all of this for us."

Cook, who missed the victory over the Buckeyes because of a shoulder injury, passed for 248 yards, and the senior broke Kirk Cousins' school record of 9,004 yards of total offense.

He was questionable entering the game but practiced in full on Thursday and felt strong while warming up.

"Obviously, sitting out stunk," Cook said. "I've been very fortunate to play in a lot of games and not have to sit out. That was a reality check and made me appreciate it that much more."

Plenty of players got into the act as the Spartans scored a season-high in points.

Senior wide receiver Aaron Burbridge caught six passes for 75 yards and a score. Junior safety Demetrious Cox returned a fumble 77 yards for a touchdown and sophomore nose tackle Malik McDowell scored on a 13-yard interception return.

Sophomore running back Gerald Holmes gained a combined 100 yards, including a rushing touchdown.

There was obviously no letdown from their shocking upset in Columbus.

"When you put us in a situation like today, when we're one game from going to Indy, there's no question we're going out and giving it everything we've got," Cook said. "When it's win or go home, we're going to play fast and we're not going to be denied, we're not going to let someone come in here and take what we want."

Junior quarterback Christian Hackenberg passed for 257 yards and two touchdowns, both to sophomore wide receiver Chris Godwin, for the Nittany Lions (7-5, 4-4).

Godwin had a career-high 11 receptions for 109 yards.

Penn State, 0-5 against ranked teams under coach James Franklin, committed four turnovers leading to 27 Spartans points.

"We were able to move the ball but we made critical errors," Franklin said. "You can't turn the ball over and make critical errors against a top team like this.

"Turnovers hurt us. Turnovers early, turnovers late -- those things are going to make it very difficult to be successful."

The Nittany Lions' starting defensive ends, senior Carl Nassib and sophomore Garrett Sickels, missed the game because of undisclosed injuries.

Without them, Penn State didn't record a sack against Cook.

"He was comfortable in the pocket," Franklin said. "We've been able to get pressure against pretty much everybody all year long. When you take your two starting defensive ends off your unit, that's going to have an effect."

The Spartans' 10-point halftime lead ballooned to 24 in the third quarter on Burbridge's 29-yard scoring catch and tight end Josiah Price's six-yard touchdown grab.

Penn State scored nine seconds into the fourth quarter on Hackenberg's five-yard hookup with Godwin. But the Spartans answered with three touchdowns in a 1:30 span, including Allen's run.

The Spartans led 20-10 at halftime, highlighted by Cox's first career touchdown.

NOTES: Spartans senior WR Aaron Burbridge surpassed the career 2,000-yard receiving milestone with his first reception of the game. He's only the second player in school history to reach 150 receptions. ... Penn State QB Christian Hackenberg became the school's leader in career touchdown passes with his second-quarter scoring toss. He entered the game tied with Matt McGloin, who had 46. ... The Nittany Lions and Wisconsin are the only Big Ten teams to post winning seasons for the last 11 years. ... Michigan State has won 10 or more games in five of the last six seasons. Before coach Mark Dantonio's arrival, it had only two 10-win seasons in school history (1965, 1999).