Line an 8-inch baking dish with aluminum foil.

Melt butter in a large saucepan over medium-high heat. Stir sugar, vanilla extract, and salt into the melted butter; bring to a boil and cook and stir until the sugar dissolves, about 1 minute.

Reduce heat to medium; add the peanut butter and chocolate-hazelnut spread. Cook and stir until smooth, about 5 minutes. Remove from heat and add the oats; stir to coat evenly. Dump the mixture into the prepared baking dish; spread into an even layer using a spatula or spoon.

Allow the mixture to cool completely, at least 30 minutes. Remove from baking dish, lifting by the foil. Cut into bars to serve.