Cut peeled potatoes in half longways. Lay potato flat on the cutting board and cut potatoes 1/4"-1/2" thick. You may need to cut those fries in half again depending on how big your potatoes are.
Toss cut potatoes in a large bowl and cover with water. Soak for about 30 minutes.
In the meantime, preheat oven to 400 degrees.
Drain potatoes and pat dry. Add oil, garlic powder, onion powder and salt to the bowl of potatoes. Toss to fully coat.
Line a large baking sheet with parchment paper. Spread potatoes on sheet and bake in preheated oven for 20 minutes. Then, gently flip potatoes over and bake another 15 minutes.
When done, potatoes with be slightly crispy on the outside and soft on the inside. Serve with your favorite fry sauce or ketchup.