Upon returning to Bob-Omb Battlefield when selecting this second star, the landscape hasn’t changed much, but there are some new things. First, you should notice that the cannon near you upon starting the course is now away. If you speak to the Bob-Omb Buddy on the raised platform at the start, he will open up all of the cannons on the course, meaning you can use them for your own reasons. This won’t be important for right now, but you will need to use the cannons to get some stars later in the course. The other new thing that you will see from the entrance of the course is a giant Koopa Troopa.
Approach this Koopa Troopa and he will introduce himself as Koopa the Quick. He heard of your exploits in defeating King Bob-Omb and figures you are probably as fast as you are strong, so he wants to race. Approach Koopa the Quick to initiate the conversation, then select that you want to race to begin it. There’s really not much to say about the race, as Koopa the Quick is fairly slow here and just taking the normal path to the top of the mountain leaves you with more than enough time to fool around a bit. The only thing that you cannot do in the race is use the cannons, as Koopa the Quick will consider that cheating.
That means all other means of getting to the summit is fair game, such as using the teleport in the alcove. Whatever you do to get to the top of the mountain, approach the flagpole to stop the timer, then wait for Koopa the Quick to get there. It takes about a minute and a half for Koopa the Quick to get to the top of the mountain, so there is plenty of time. Approach him after winning to get the Power Star.