To me anything between 2-4mins, averages high single digits to low teens gradient is a punchy climb. Climbs that I can big ring on a good day but usually have to go to small chainring if I don’t want to get dropped in a group ride. Anything that kind of cramps up my abs is a punchy climb haha.
Tons of climbs fit that description in Monuments/Spring classics. Mur de Bretagne is a punchy climb. It is regularly used in the TdF as a finish. It’s also Stage 2 finish this Sunday. Valverde has the strava KOM but Dan Martin may have the true KOM. But I’d suggest you give Valverde’s climb a look, It’s like a lesson on pacing. Follow Bala on Strava to see this activity. Join for free.