Add the dulce de leche to a bowl. Sift in the icing sugar and stir until smooth.
Add the salted peanuts and stir to combine.
Pour the topping over the cheesecake.
Cover and refrigerate for at least three hours or, ideally, overnight.
When ready to serve, remove the outer ring of the springform pan. Let the cheesecake sit at room temperature for a little while as this will soften the filling slightly and allow the dulce de leche to gently drip over the sides.
Slice into 10–12 small servings. Enjoy!