3/4 cup all-purpose flour
1/2 teaspoon salt
3/4 cup whole milk
1/4 cup heavy cream
2 tablespoons butter, melted, plus more for cooking
1 egg
1/2 cup chocolate hazelnut spread, such as Nutella
4 bananas, sliced into 1/2-inch-thick rounds
1 can store-bought potato straws
Powdered sugar, for dusting