Fill 4-quart Dutch oven one-third full of oil for frying. Heat over medium heat.
Meanwhile, place hazelnut spread and dulce de leche in microwavable dish. Microwave on High in 10-second increments, stirring every 10 seconds, until smooth. Pour mixture into decorating bag with small tip or condiment container from local cooking store. Set aside.
Place cinnamon-sugar in shallow dish; set aside.
Separate dough into 8 biscuits. Using doughnut hole cutter, cut out several rounds from each biscuit.
Fry 6 to 8 dough rounds at a time, turning constantly with spider or metal spoon, until golden brown. Remove from oil; place directly in cinnamon-sugar. Carefully turn doughnut holes in sugar until coated. With sharp knife, pierce hole in each doughnut hole. Insert end of decorating bag; squeeze bag to fill with hazelnut-caramel mixture.