Step 1

Melt butter in a large skillet over high heat. Add pineapple, sugar, and oats; cook, stirring and scraping bottom of pan, 5 minutes. Reduce heat to medium-high; cook, stirring, until sugar is caramelized and pineapple softens, about 5 minutes more. Stir in lime juice. Spread mixture in a single layer on a rimmed baking sheet, breaking up any big chunks; let cool slightly.

Step 2

Spread yogurt in a large dish. Top with pineapple mixture and hazelnuts. Serve immediately.