First, grind the salted peanuts in a blender until they become a powder, being careful not to over-process into a paste. Mix the ground peanuts with brown sugar in a bowl until well combined and set aside.

Take your lumpia wrappers and carefully separate them one by one. Place a wrapper on a clean plate with one corner pointing toward you. Put one teaspoon of the peanut-sugar mixture near the bottom corner of the wrapper. Fold the bottom corner over the filling, then fold in both sides. Roll the wrapper upward tightly, like a small burrito. Dip your finger in water and dab it along the top corner to seal the roll. Place the finished roll seam-side down and cover with a slightly damp cloth. Repeat this process with the remaining wrappers and filling.

Heat cooking oil in a small saucepan over medium heat until it reaches 350°F (175°C). Reduce the heat to low. Gently place several rolls in the hot oil, being careful not to overcrowd the pan. Fry until golden brown, about 3-4 minutes, turning occasionally for even cooking. Remove with a slotted spoon and drain on paper towels.

If you want to add a caramel coating, add ½ cup sugar to the hot oil before frying the rolls. Keep the heat on low and wait until the sugar floats to the surface. Then fry the rolls as directed above, being extra careful as the caramel can burn quickly.

Let the turones cool slightly before serving. They can be enjoyed warm or at room temperature.